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Chapter Text

The school bell rings and every student started to leave the building. A girl stood in front of her table and packed her bag. Today was the last school day of the week and everyone is excited to leave their exam weeks behind them and have fun with their friends. Today is also the day where Yuzuki can pick her brother up on time. 

She is smiling while she packed her bag, she tried to leave the school grounds as soon as possible. 

“Hey, Yuzu-chan. Are you free tomorrow? How about we go to this new cafe that opened near the train station?”

“Yeah, how about we go?” 

Yuzuki looks up and shakes her head “Sorry guys.” she smiles apologetic.

Moans of disappointment surround them when they hear her answer. 

“Well, I guess we cannot do anything about that. Maybe next time, ok?” 

“Yeah, definitely.” Yuzuki exchanged smiles with them before leaving their classroom together. 

They continued to talk as they left the school grounds and parted ways at the gate as Yuzuki had to walk a different way than them. All of her friends needed to go to the train station while she has to go somewhere else before she goes back to her residence. 

The sun was starting to set when she was halfway towards to her destination. She came across a crossroad, with her nose in a book and an rocket science book under that. From her right side came a boy a little older than her in a high school uniform, he was carrying a big odd shaped bag with him. When they passed each other his bag got stuck to her keyring that was hanging from her school bag and Yuzuki got dragged bag. 

The boy turned when he felt the pull and saw her falling towards him and tried to catch her before she met with the asphalt. Both of Yuzuki’s book fall to the ground when she collides with the boy together. The boy wrapped one of his arms around her and pulls her towards him. 

Her back collides with his chest.

They groan as the pain registered in their brains. 

“Are you ok?” the boy asked, ars circling around her waist. 

Yuzuki nodded as she moved further away, “I’m fine.” she turned around and looked at him meeting his blueish eyes “What about you?” She gazed at him worriedly.

He smiled reassuringly at her and shook his head “I’m fine don’t worry.” He reached his hand out and brushed his hair back that fell in front of his face.

He stood up and reached out a hand to help her up from the floor. When they stood back up on their feet their gathered their stuff and parted ways. 

Yuzuki turned around and instead of opening her book she placed them in her bag and continued her way towards her brothers school to pick him up. 

While Yuzuki was on her way to her brother the boy picked up his things and started to go on his way too. But before he got on his merry way he looked over his shoulder and gazed at the mysterious girls before shaking his head and turning back around. A small smile grazed his face as he looked down and placed his hat that he picked up on his head. 

________________

The sun was starting to set when she arrived at the school gate of her brothers school, but she saw someone she didn’t expect. 

“Byakuya…” She mumbled as she saw the white-grey haired man in front of her brother. 

She tightened her hand on her school bag strap and walked closer. While Byakuya seemed to be talking her brother has noticed her and looked around the old man. 

“Onee-san.” Senku Ishigami, her younger brother by 5 years walked around the old man as she neared. 

“Hi, Sen.” She smiled at him before looking towards the other individuals “Byakuya…” She pressed her lips together as she turned her eyes towards him. 

Chapter Text

It was Presentation day and every University student had to present they mock thesis in front of their whole course this week. A familiar mob of white hair in a cap sat more to the front of the lecture hall.

A few others presented before the professor called out the next student to present. Everything fell silent, you could have heard a pin drop at how quiet everyone became and Ukyo looked up confused before his eyes locked on to the figure of the familiar girl. She was walking to the computer and plucked her USB into it. Everyone was holding their breath either by her beauty or because they knew who she was.

“Good morning, everyone.” A smooth and angelic voiced travelled through the room and entered Ukyo’s and everyone’s ears. Ukyo had subconsciously sighed as if he had waited for this voice for eternity. After greeting everyone she started to introduce her theory. Something that stumped him was that her topic was on a complete new level than everyone else’s and it was so complicated in theory. But he realised that even though it was extremely complicated she was explaining as if it was the weather forecast. her easy going nature also helped. Ukyo’s interest got even more peaked when she had mentioned sonar and how voices travelled, with theories that already exist but also with her own input on how it could be false or deceiving as the time went by and more and more technical advanced the world became.

The bell rang at the same time as she had finished her last sentenced, Ukyo could hear some sighing in sadness, but if it was in disappointment that she stopped talking or because they had to leave the room with the smart beauty he didn’t know. He slowly packed up as the other students also filtered out of the room. when he had picked his backpack up he walked towards her as she was standing at her seat with her report for the presentation. He walked towards her.

Ukyo placed one hand in his pocket while his other reached up to his cap to adjust it one his head.

“H-hi” He swallowed as his eyes met hers.

“Hello.” She smiled as she zipped up her back before turning to him.

“Your presentation was really amazing, especially the part with sounds and echoes.”

“Can I ask you how you decided on this topic? I would really like to talk with you a little more about it. Or more like you telling me more about it, I-I’m trying to become Sonar Operator.”

“Oh, that’s really interesting for a job choice. Sure, I have nothing to do today. If you have time how about we get lunch and something to drink while we talk?” She looked at her watch before looking back up to him.

Ukyo returned the smile and waited for her to finish taking her stuff before they left the lecture hall together. 

Chapter Text

Time passed and Both of them became really good friends, well at least that’s what everyone else is thinking they are. Other time they had developed feelings for each other. But of course only after Ukyo had overcome his shock about how smart she actually really was, she also helped him study to become a sonar operator.

They started dating after they had known each other for 6 month as they continuously felt they were more than friends and it came apparente on one day when a guy was talking to her, while she was waiting for Ukyo. The guy she was talking to her was one from their class that they shared, so Ukyo knew who he was but she didn’t because she didn’t go to a lot of classes, she only went sometimes when she had time. 

“And maybe if you have time of course, you could come to our study meet ups. And we can get to know each other better.” the guy said as he placed a hand on her shoulder. 

Yuzuki didn’t say anything and just smiled, she was extremely uncomfortable with him especially because she didn’t know him. 

“When is Ukyo going to arrive?” 

The guy became a little more than touchy and she had tried to subtlety remove him multiple times until Ukyo came and saw what was happening. He walked closer until he could reach her before hugging her from behind and resting his chin against her shoulder while staring at the guy in front of her. 

“Can I help you?” His cap he was wearing threw a shadow over his face which made him look even scarier. 

The guy started to sweat and gave a hurried goodbye before running back to his friends.

As the group was running away, Ukyo had turning her around so she was now in his arms facing him. She was chuckling a little and pressed a finger against his hat making it tilt up so she could see him better. Before she reached up and smoothed out his frown between his brows.

Ukyo sighed while squeezing her waist a little as he rested his forehead against her shoulder, letting the bag he had on his wrist dangle around and hitting her side softly. She wrapped her arms around his shoulder and gave him a soft kiss on his head behind his ear as she chuckled a little. Before burring her face into his neck and whispering.

“I love you.” Because in that moment she could confirm that he cared for her more than what a normal friend would. She had her suspicion for some time now but wasn’t 100% sure or maybe it was because she was also in love with him but didn’t want her feelings come in the way and let her head make something up that is not true. She could feel Ukyo freeze up before lifting his head up a little to look her directly into her eyes.

“Did you just…” His eyes widen as he looked into her bright face before cupping her cheek and pulling her into a kiss while his other arm hugged her to him. His hand on her cheek moved towards her hair and weaved between her strands as they kissed each other, she had her arms still around his neck when he suddenly kissed her. But she didn’t hesitate to kiss him back.

He hesitantly removed himself from her but stayed close enough to look into her eyes with their nose touching.

“I love you, I love you so much.” He chanted before kissing her on her nose and smiling warmly at her.

Chapter Text

Senku had known that she had a boyfriend and who it was, but he had never meet him before. He was happy for her because she never had anyone else who could understand her so well as he and their father did. So when she told him that she would introduce him to them, he was a little nervous, even though he would never admit that. He didn’t know why, the only thing he knew was that his sister had a better understanding in people than he had and he learned a lot of things from her. 

But he trusted her enough so he calmed down and continued to work on his project at the chemistry room they had in his school. He was 12 and was already extremely smart for his age he had at some point skipped a grade, but his sister hadn’t let him skip any more than that and also talked with their father about it because it wasn’t really good to skip to many, she still wanted him to experiment a normal, even if it is not, childhood. The reason for that is because she had skipped a lot and it didn’t really help her with socialising or making friends apart from going to places were people her age were.

When the time came Senku packed everything up and walked towards the gate. Today his sister was going to pick him up as their father had something come up and would be later at home than usually. When he arrived at the gate he saw his sister smiling at him. But at closer inspection he saw a guy standing a little behind her holding her hand. When he neared her he saw that the guy had white hair, the same white her they had but without the coloured tips and that he was wearing a hat, but what really peaked his interest was the way that guy was looking at his sister.

Eyes filled with warmth and love, the way his sister always gives him but a little different. In that moment he knew that her boyfriend was really in love with her.

“Hi, Senku. How was school today? Did you finish you project?” His sister pulled him out of his train of thoughts as he looked up at her.

He nodded “Yeah, i have it with me. I just need to finish up some wiring and it would be finished.” She smiled proudly at him.

“That’s amazing, can you show it to me at home when you are finished?”

“Yeah” He smiled brightly excited to show his newest project. “It’s going to be exhilarating, 1 billion percent.”

She smiled and took his backpack for him. But before she could put it on her shoulder as she usually did, a hand reached out and took it for her.

Both Ishigami’s looked other and saw the white haired man look at them. Ukyo looked at his girlfriend who didn’t protest before letting his eyes wander down to the younger one.

“I’m Saoinji Ukyo. It’s nice to meet you Senku, sorry for the late introduction. Hope you don’t mind if I carry it.” He asked while holding up the hand with Senku’s backpack.

Senku looked from him to his sister who waited for his answer before he looked back and shook his head. He than proceed to take his sister outstretched hand and they walked like usual back home hand in hand. The only difference was that another person was on the other side of his sister walking with them.

His sister had reached out with her free hand and smoothed over Senku’s her letting some fly away place themselves back to his gravity defying hair. Senku continued to talk about his theories and asked his sister about thinks he heard or read about and wanted to know the truth and if his teacher was spouting nonsense again or withholding information when he asked stuff.

Ukyo sometimes pitched in when they talked about thinks he actually completely or partly understood and also asked some questions on his own. He was used about her smartness but didn’t think that her younger brother was also as smart as she was. The atmosphere around them was nice and comfortable.

Chapter Text

At some point they arrived back at the Ishigami household and Ukyo handed Senku his backpack back to him as he had finished taking his shoes off.

“You know the drill, Sen.” His sister told him and he nodded, walking up the stairs to wash his hands and taking his school work and project out before taking his project downstairs with him to the living room were the rest of his sister’s tools lied. He mostly uses her tools as he didn’t had his own and it was also illogical to own two copies of all the tools when they both live in the same house.

While he continued on his project, quiet music was playing around the house and the couple were in the kitchen preparing the food for dinner.

She was cutting some vegetables when Ukyo came up behind her and gave her a kiss on the side of her face.

“The bowls are above you, right?” She nodded as a responds.

He placed a hand on her waist and moved her a little to the side so the door wouldn’t hit her before taking out four bowls and a few plates to dish out the food. He placed them on the counter next to her before opening another drawer to take out chopsticks. In that moment Senku came into the kitchen that was connected with the living room and coming to a stop next to his sister, waiting for her to finish cutting. When she reached out to the next thing to cut senku spoke up.

“Nee-san, Do we still have some baking soda left?” She looked down and sees senku as he had grabbed her sweatshirt subconsciously like he always did.

She hummed before nodding her head. “I think so, they should be on the top shelf were they always are.” She said before letting her eyes drift over Ukyo. He got the message and walked towards the cabinet he had opened before.

“I think I saw some when I go the ingredients.” Senku walked over without a second thought and stood next to him.

He looked up at him and waited for him to give him the baking soda. But before he could even think about the next step for his project he realised that Ukyo was not wearing his hat and he could see his face more easier than before.

“Here you go.” Ukyo smiled and handed it to him, “Is this enough, if not there is still a new pack.”

“no, this should be enough.” Senku shook his head when he looked down into the pack he was now holding in his hands.

“Sen, is it going to make a mess?” His sister voiced.

“A little.” He whispered.

“Than do that after dinner please, we are nearly finished.”

Senku nodded and went to the living room and prepared everything but didn’t continue his project, even though he really wanted to, but he knew it’s probably going to be very messy and both of them knew how hard it was to get baking soda out of everything, not only his hair.

Chapter Text

“Sen, don’t forget your lunch.” A 22 year old Yuzuki looked around the corner to her brother who was preparing to leave the house for school. He was putting on his shoes when he looked over his shoulder. 

“Mmh? Oh, yeah i nearly forgot.” Yuzuki reached him and handed him his bento. “Thanks.” 

She hummed as she looked at her now 15 year old brother before shaking her head. 

“Don’t let anything explode again, you hear me? I really don’t need the school calling me today because something went wrong with one of your experiences in the chemistry room.” 

“Yeah, yeah, don’t worry.” Senku put his bag on his shoulder before he turned around in realisation. “Oh, yeah. You are meeting Ukyo today, huh.” He smirks as he looks at his Onee-san. “What you scared I’ll ruin your date today?” He chuckled a little evilly. 

Yuzuki just looked at him before a phone call interrupted them. Yuzuki rolls her eyes shoos him out of the door. “Just go to school would you.” She says before fishing her phone out of her pocket and answering. “What is it, Byakuya?” Senku rolls his eyes and walks out of the door with a wave. 

While he is on is way to school, Yuzuki talks with their father and listens what he had to say while she got ready to meet Ukyo later. 

“Ok, yeah, I understand. Hey, Byakuya I really need to go now.” 

“Ok, sure, you two be safe ok, darling. And greet your little boyfriend for me.”

“Will do and don’t annoy your colleagues too much.” before Byakuya could say anything he only heard the peeping from the phone, signalling him that the call had ended. 

Yuzuki sended Senku a message to inform him that she would be going now and would text him when she was on her way home. Immediately after she had pressed send she got another call and this time it was from the person she would meet in a little bit. 

“Hi, Kyo.” 

“Hello, love. Are you on your way?”

“Yes, I just went out of the house.” 

“That’s good. Be careful on your way, ok?” Ukyo had nodded his head before he answered but realised that she wouldn’t be able to see his action and chuckled a little at his silliness. 

“Oh, by the way, Byakuya says hello.” 

“That’s nice from him, greet him back for me when you talk with him next time.” 

“I will.” Yuzuki smiles as she looks down at her outfit she had picked up for their little date. Today would also be their last date for some time as Ukyo got accepted as a Sonar operator for the next expedition. So many of the marines were getting everything ready on their ship while Ukyo got a day off with some others to spent some time with their family and friends before they set sail. 

“Did you take everything with you you need for today?” Ukyo’s soft voice sounded from her phone. 

“Yeah, I have everything I need.” Yuzuki looked at her hands to see if she forgot any of the jewellery, she doesn’t really take them off but today while preparing Senku’s bento she took off her rings. Most of her jewellery matches with what Ukyo wears or is something he had gifted to her other the three years they had been together. One of which is a greenish blue ring, he had given her that as a type of promise ring, it was a ring that was in his family and his grandma had given him that ring to give to someone he truly loves. 

“I really miss you” She mumbles. 

Ukyo chuckled “What do you mean you miss me? I’m still here aren’t I?” 

“Yeah, but you will be so far away and I can’t even contact you” 

“Don’t worry, what do they say, the distance make us fonder of each other or something like that?” 

“Mhm… I’ll miss you either way.” 

“I know and I will too. Love you, Zuki.” 

“Love…. Wait.. What is that?” 

“Zuki? Yuzuki!” 

Yuzuki couldn’t answer him anymore as the green light had frozen her into stone and her phone had dropped down onto the floor. 

In seconds every human creature was covered in stone as the green light had passed them. 

The only people free from harm are those who witnessed this strange phenomenon in the skies above.  Saved by space but hurt by the loss. 

Will humanity be lost? Or will the witnesses find a way to bring it back. 

“Senku… Yuzuki…”

Chapter Text

Senku had entered his school lab and continued to work on his project that would melt and destil plastic into gasoline, that is colourless and had a faint smell that is hardly detectable unless you know what you had to look or more smell for.  

The lab door bangged open and shocked everyone in the chemistry lab while a loud guy stepped in before Senku could melt another batch of plastic caps. 

“LISTEN UP, SENKU!!! I’VE DECIDED! TODAY IS THE DAY!!!! THAT I’M,  GOING TO TELL YUZURIHA THESE FEELINGS I’V HAD INSIDE FOR THE LAST 5 YEARS!!!”

Everyone in the lab hid behind the table as they heard him scream while Senku ignored him and continued to work on his project as if it was a normal sunny day outside. 

“Oh? Well, well… that is something quite interesting indeed.” he twisted the last glass bottle into the machine before completely turning around to look at his childhood friend. “I’ll be cheering you on so loud, my vocal chords might tear… From here in the science classroom, that is.” 

“OH, GREAT. THANKS A TON, SENKU!” 

“Ugh, shut the hell up already… As if I’d give you a millimetre of cheering , you great big oaf.” 

“WHAT?! MAKE UP YOUR MIND!!” 

“Besides… You haven’t said anything for 5 whole years? How stupid are you?” He stuck his pinky into his ear as he berated his friend. “That’s completely irrational, illogical. Even my sister’s boyfriend confessed his feelings for her faster.” he gave him a ridiculous look before turning back to the table and picking a glass flask filled with an unknown substance. 

“But I guess I’ll give you a method so rational and sound it’ll knock you off you feet.” an evil smile painted Senku’s face as he turned to his friend with a flask “By having you release pheromones, you’ll drive your ability to stimulate to the extreme. In other words, it’s kind of a love drug.” He hands the flask over “In other words if you drink this, It’ll be 10 billion percent in the bag!”

Taiju held the flask in both of his hands and kept silent, every single one in the lab that didn’t know what he would do anticipated that he would drink it as Senku’s best friend but they were surprised when he, without hesitation poured everything into the sink. 

“Thank you, Senku! But I’m sorry. I don’t want to depend on this kind of underhanded trick.” the determination and confidence was written all over his face as he declared his decision to him. 

He turned around and left everyone in the lab behind as he made his way to the pot he asked Yuzuhira to wait for him. 

At the one and only tree in the whole school was a girl waiting as she watched the sun set slowly. Meanwhile Taiju walked up to her determined to tell her all the feelings he felt for her even though it took him 5 years to actually tell her that. But no matter how long it would take he would always love her and tell her that. 

“That’s right… I’m doing this fair and square. I’ve called Yuzuhira out under this camphor tree and I’m going to tell her how I feel!!” 

All the boys in the lab had blush rush up their faces when they looked in the sink wanting to know if it was really true that Senku had created a type of love drug and that it was just now flushed down the drain. But luckily for them one decided to ask him the question everyone was thinking about. 

“But that love drug you were talking about… is that for real…?” 

Senku pulled out a match and lit it up on fire before he threw it into the sink were the liquid was still swimming around. As he was answering a loud explosion happened and everyone ducked for savety. 

“As if something like that actually exits. That was just regular old gasoline. I refind it from these plastic water bottle caps.” He threw some caps that  he was talking about in his hand as he gave them a deadpanned look. 

“THink about the molecular structure of polyethylene for a sec, morons.” Senku was chuckling and daydreaming as he thought about the structure and formula like a school girl in love. “It’s just Hydrocarbons spliced off the gasoline. You can tell just by looking, can’t you?” 

“No…. we….can’t…” 

“Not in the least…”

“Though I think Yuzunee could probably make something similar as a love drug, was it Oxytocin, maybe aphrodisiac or something.”

“But wait a second… if Taiju had drank that, he’d have died…” One of Senku’s labmates showed concern for the oblivious student while the others still tried to think how Senku could actually see the chemical structure of liquid just by a glance. 

“Kukukuku… it was a 10 billion percent chance certainty that he wasn’t going to drink it.”

He turned to look at them with a self knowing look “that straight arrow, sincere idiot…” he said with a warmth, but he would never admit that he actually cared for a the big oath that he called his friend. 

At some point all the students, or more the guys, walked out of the classroom. They looked out of the window to watch the confession, that was happening out in the courtyard and watch their classmate getting dumbed by the pretty girl in their year. 

“I’ve got 100 yen on him getting full-on dumped.”

“I’ve got 500 yen him getting dumped.”

“1000 yen for me.” 

THey all chuckled as they watched the interaction while Senku got himself a drink from the vending machine and adding his part of the bet. 

“I’ll put 10000 yen on him unexpectedly not getting dumped.” 

“Seriously?!”

But before the confession could actually happen an unexpected event happened and everyone looked out toward the horizon were a strange green light covered the whole sky. Taiju told Yuzuhira to hold on to the tree as he ran in front of her as he tried to protect her from it. Senku took a sip of his drink when he noticed the light. Before the light could engulf him completely his last thoughts went to the only person that was out there far away from him. 

“Shit, Nee-san!!!” 

And thus, Humanity vanished from the face of the earth for thousands of years

Chapter Text

While Senku was lying on the now green ground and counted his days, no years away trying to stay conscious he tried his best to keep notice of how much time has passed. 

“1,2, 116.427.065.520 seconds, Goddamnit.. It felt like my consciousness was being pulled away again… it seems every 800.000 second cycle, it peaks. Kukukuku… it’s just like having Diarrhea.” Even in a state of frozeness Senku was able to keep his consciousness alive without a fail, only nearly falling into an eternal sleep. “I’ve got to keep thinking and counting at the same time. I’ll partition my brain and have it work in parallel. 116.427.065.530 The amount of time that’s passed since I’ve become unable to move… 3689 years, 158 days.” 

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At some point Senku was able to break free and luckily for him it was spring time so he was able to find resources without freezing his ass off and even though he was being watched by monkey’s who thought that he was a shiny monkey he could make fire and built a shelter for the first 6 months before his new partner woke up from his sleep. 

Both of them started to make adjustment to their dynamic and set off to work. Taiju took over the labor part of everything while Senku kept his focus on trying to rebuilt the civilization and making sure that the big oath wouldn’t kill them with the supplies he gathered for them. 

“The time it took humanity to climb from the stone age to ou previous civilization… was 2.000.000 years. But we’re going to dash all the way back to the top all at once.”

“And take back the world! And I’ll identify the scientific cause behind why we turned to stone, and how we were revived….” 

“And then I'll save Yuzuriha!!” 

“We two high school kids… are going to rebuild civilization from zero.” 

“Even though it would be easier with Nee-san by our side. But I guess I’ll have to find you and revive you myself if you haven’t broken out yourself.”

“We’ll become the adam and eve of this stone world.” The fire crackled and burned strong between the two teens as they declared their plans for the near future “Now things start getting exciting!” 

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Water splashed against the shore as the sun slowly rises and exchanged its place with the moon. The stars went to sleep for the day and every single animal started to wake up from their sleep. 

Stone fragments were scattered around at the shore line as the birds start to peck around for their food. The cool air that started to slowly warm up let a lot of the animals awaken and more and more could be seen walking the grounds to find their breakfast after a long sleep. 

Birds rushed into the air when a biped came closer to them. A woven basked hanging from the upper body, body clothed with fabric unknown to any animal and legs glad with leather. Hair tied back as the biped hummed a soft tune early in the morning. 

Current date, February 26, 5738.

34 days before a younger scientist breaks free from his petrification. 34 days before another group of monkeys see another shiny monkey, but that time with gravity defying hair. Even though the hair colour is very similar the hair style is very different from her genius brother. 

Yuzuki had been awake for quite some time now already and had built everything that she needed to survive in the area she deemed to be safe. At the sea line to the ocean which provides enough food sources as well as water that she could destil to clean water if necessary. But she still preferred the little river that was a further in the forest so she could wash and drink from. 

In the early mornings of this specific day Yuzuki was walking the shore lines in search for more seashells so she could create her hygiene products for the month. 

But it seems like that this time of the day not a lot of shells got washed up into the shores so she walked until she reached the end of the beach and hiked up the little hill to the little shelter she had built for herself. There she entered her storage room and placed the basket next to her working table. 

Without rest the older Ishigami worked from the first rays of sun until they disappear to let the moon and stars take place in the sky. Since the winter time had just ended not a lot of animals had woken up yet so after she had prepared enough ingredients for the next few months she started to pack her bag and pulled out some paper and a charcoal pen and made her way back out into the wild. 

“Ok, now let’s see how this country had changed. I guess the mountain formation should have changed a little. Mount Fuji should be even taller than now. But I guess I’ll estimate how tall it is now and calculate it. It would take days to actually walk up there. And I don’t really have the fitting equipment right now. Maybe I’ll let some experienced climber do that when we are caught up to our own era again. The water level should also be higher now. But I gues the tectonic palace should have move a lot of mountains now. Especially under the ocean sea level.”

Yuzuki mumbled under her breath as she walked to the place she had left off last time. She prepared for a few months already to set off on a ‘small’ expedition to see the landscape changes over the the thousands of years were humans were not present. 

“I guess a lot of plants revived too. That’s good. They probably wouldn’t really exist anymore if humans continue to walk around this planet for how long we have been frozen in time.” She hummed and nodded her head as she looked around and watched the nature around her live and thrive without a care in the world like it has always done. 

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Taiju was walking around and gathering food when he stumbled upon a gave opening. 

“That cave opening… that's where I laid for thousands of ears, isn’t it…” 

He walked closer to it and found something he wouldn’t had expected. 

“What is this?!” he looked down and saw something dripping down into a cup “Whoaaaa! This means someone else other than me and Senku survived, right?!” Tears gathered in his eyes “Someone must have left it here!! Maybe Yuzunee!?” 

“No, it was me, moron.” Senku suddenly appeared behind him with his pinky stuck in his ear. 

“YOUUUU?!” 

“Yeah… there really aren't any other humans left in the world…” Taiju said dejected and looked to the side glancing at the cup. 

“Repopulating humanity! That is our most important task right now. And if my sister really were alive and walking around here somewhere do you really think she wouldn’t have helped us by now… And you really think there’s any future humanity in us two dudes just lazin’ it up out here?” 

“You got a point!” 

“And besides. After 3700 years passed, what was the reason that we broke free of our petrification?”

“Ahhhh… Maybe the stone went bad?” 

“Mmmm.. If we were to say that this mysterious mineral eroded…” Senku thought about Taiju[‘s idea a little “Kukuku…. Then it’s even strange isn’t it, that the two of us broke free almost the same time? After 3700 years, we were only half a year apart. This can be no mere coincidence there has to be a rational, logical reason for it!!!” 

Senku pointed out to the two spots were he woke up and where he digged out his friend “Like you, I was washed away down near the entrance to that cave as well, but…” now he pointed at the ceiling of the cave “Look… you see that there dripping down?” on the ceiling their hung a colony of bats resting around the spot that dripped a mysterious substance. 

“It’s miracle water born from the dropping of these bats. Nitric acid.” 

“DID YOU SAY NITRIC ACID?!! Err… so what? Sorry, Senku.. I have no idea what that means.” 

“I thought I told you already, you great big oath.. It’s too much of a pain to have to try to explain anything to you.” 

Both of them returned to their camp and Taiju watched Senku pouring some kind of liquid he had refined down onto a petrified bird. 

“Ohhh! I get it! So if we put this nitric acid on it the stone will go bad , and it’ll come back to life?!” 

“If it were that easy, I wouldn’t have any problem.” He sweatdropped at his friend and returned the bird to the other one in the lab shelter were hundreds of those petrified birds laid after each failed experience he had done on them. 

“I’ve tried a ridiculous number of times already using different methods and different materials. Over and over…” He reached up and placed it on ts shelf and named the percentage of the liquid combination he used. “And over again…” 

Taiju just stood frozen at the door as he saw the amount of birds Senku had experimented on for 6 months now and couldn’t believe his eyes on how many experiment he had already done. 

“But it’s all in the realm of fantasy for now. Are these even minerals? Do they have cells? There’s not even equipment to research with anymore.” 

“So then there are things in this world even science can’t explain…!” 

“Kukuku… and there it is… the ol’ cliche.” A smirk danced on the scientists face “That’s why I keep coming up with hypotheses and experimenting! Scene is straightforward and honest. If only we had some Sake.” 

Senku started to explain his thought about using the Alcohol in sake and mix it ith the nitric acid and hoping to make a fluid that would break the birds free from their cages. 

“We can make Nital. It’s a corrosive solvent used for etching among many other industrial uses.” 

“What did you say just now… What did you say, Senku?” 

“Huh? Nital. It acts on the grain boundary of ferrous minerals…”

“NOT THAT! I’m not gonna understand difficult stuff like that?” He told the mad scientist shocked “You said ‘if only we had some sake’ right?!” He pulled out some grapes he had gathered from earlier out for Senku to see “Well… with these grapes column’t we make wine?!” 

Senku looked shocked at Taiju’s finding before both of them looked at each other. 

“NOT BAD AT ALL! YOU GREAT BIG OATH!!” 

Now came the labor, Senku started to squish the grapes carefully into a bowl he had created, which would have taken him weeks if not months to finish and actual batch that would be enough to make the fluid. But surprisingly Taiju came up with a better idea which would make the progress much faster for them. He put every single grape he had found into a big bowl and started to stomp on them making a big mess, but this cutted their labor hours short to a day of work only. 

“Ahh… yeah… I’ll leave all the manual labour to you and your cheat-mode endurance. Yeah. that would be the most logical.” 

After three weeks the thousand of year old teenagers made their first batch of wine that was drinkable even if it wasn’t enjoyable. 

“Oooh! It actually game out way better than I’d expected. It’s only about 10 billion times worse than what you’d find in the store.” He swung the wine around in his cup after he had taken a sip from it while Taiju was spitting and coughing front he bitter taste. 

“One step at a time down the path Forward! We’rre gonna break some bones to keep up from here on in! Let’s begin… wine distillation!!! How to make Brandy!”

Chapter Text

Now that they were able to finish making the miracle fluid it was time to decide who to unpetrify first. Of course Senku would have love to free his sister but he had no clue were she was or where she was buried, so he had only one choice. 

“Taiju… We’ve got your grapes to thank for this. So you can at least decide the first person we’re going to save.” 

Meanwhile both the teenage boys were busy depetrifying the world and getting a head start on bringing the world back to its original modernisation. Yuzuki was slowly drawing a map from her route she was taking and sketching every plant she came across in a different small scroll she had created by skinning some animal skin from the animals she had hunted and dried to make some kind of paper were she could draw out the map. She also created a piece of charcoal from the ashes of her fire she lit up every evening and morning. 

“I really need to find something over that this piece of leftover skins and vines to wrap this. It’s not holding up very well.” She looked down at her now black finger tips as she hiked up the hill. 

“I should also search for long but thin vines that I can weave into some sandals. These skin shoes are not ideal to hike.” She sighs as she looks around, looking for dried long grass. 

After some time she had found what she wanted and cut a chunk with a stone she had sharpened before sitting down on a flat stone and started to weave them into soles. 

“I’m thinking, how long would it take for Senku to depetrify from these stone fragments.” Yuzuki looked thoughtful as she intertwined the straws. 

“What would Kyo think about all this…” Yuzuki stopped in her movement and lowered her work. “I guess it is pretty lonely…” She chuckled sadly. “Well can’t help it. I guess the time for emotions have to wait for now.” After a deep breath Yuzuki continued with her work and connected her straw sole with her shoes to make them more sturdy. 

After putting on her new shoes she stood up and tested them. “They will do for the time being.” 

Yuzuki continued on her way as she thought about what to do next and where to go next. 

“Should I continue on the sea side? Logically it would save some time to make this map.” She looked down on her map and tapped her pen on it. “But that way is too dangerous as I don’t know how the geographic has changed or which animal now live there. But most animals from the zoo don’t live near the ocean so that shouldn’t be much of a problem.” 

Coming out of the trees Yuzuki found herself on a cliff where she could see the ocean and most of the edge of Japan that connected with the water. 

“Now I’m at the edge of Miura in Kanagawa. 35°10'08.1"N 139°37'03.8"E.” 

Yuzuki hummed softly as she thought were she should go next. 

“Maybe I should put my next stop to Mount Fuji…? No. How about Mt. Hakone?” 

She looked across the Sagami Bay. 

“Mt. Hakone is 35°11'22.02" N 139°01'35.36" E. It’s 80,4 km from here. That would take me about 19 hours and 22 minutes if I walk continuously around the sea side. But that I’m not Senku’s friend.” She chuckled. “Give or take around a week.” 

“Well than I should get going. If I cover more ground and add more details to my map… I’ll probably reach Mt Hakone when Senku is alive. But he’ll probably only go there if he was in real danger.” 

Yuzuki picked her stuff back up that she had out down for her break and continued to walk to her new destination while collecting everything that she deemed helpful in the future and documented all the changes in nature and those that stayed the same. 

Yuzuki walked all the way to Mt Hakone but she did stray from the path. Not pressured by the time as she admired the nature and the changes Mother Nature did over the time all the human beings had became stone. 

“Mother Nature knows no mercy, she never had, so why should she have started now when we all left everything back into her grasp.”

61 days have passed, two months since Yuzuki had broken free and 61 days since she started her journey on bringing back the modern time and the new knowledge from this familiar yet unfamiliar world. 

As much as Yuzuki wanted to but she had to keep in mind that she needed to travel light. At some point probably only a few hours after she had started her journey to Hakone she stopped writing down any new information. The amount of skin she would firstly collect and carry would only slow her down so she concentrated on her map and only collected the most important herbs that would help her with wounds, fever, and infections. 

Yuzuki walked all the way back to Sagamihara before walking back towards the ocean to Fujisawa. She kept her pace slow so it took her a while but she didn’t mind. Meanwhile Senku had finally learned how to make fire and had built a shelter with all his remaining stamina every day that he had now time to actually find a cure for this petrification. 

“If only that big oath would wake up…” he thought exhausted leaning against the tree of his tree house while watching his fire. 

“Or Nee-san would be enough too. If only I knew where her body was…” Senku gritted his teeth. 

_____________________

Somewhere far away half underground was a body who struggled with himself to stay awake over the years but always fell asleep. But he didn’t want to give up. “I need to stay awake. Only one last time, I want to see her one last time.”

_____________________

Back to present  

“It’s been a year since I started this experiment and this was after how many dozens.. How many hundreds of failed attempts…” Senku leaned back after having watched the the now free bird fly away. “Kukukuku… That straight and steady path it gets there faster than you’d think.” He was completely exhausted and looked up into the sky “In the end… science… triumphs over fantasy. Now I’m getting excited…!”

Quickly he went back to topic and looked at Taiju. 

“Taiju.. We’ve got your grapes to thank for this. So you can at least decide the first person we’re going t save.” he points out as he smirks. 

“Thank you, Senku!”  “My answer should be obvious..!”

Both of the boys made their way towards their old old school tree were their friend has been kept for a thousand years. And now, after one year of starting civilization over from zero the power of science has created water of revival that can free people from their petrification. 

“So if we put that water on her Yuzuriha will be revived from that stone, right?!” Taiju exclaimed with excitement as they stood in front of the tree. 

Senku smirked as he answered “Yeah… In my tests, when i poured the water on the statues lying around… they all properly turned back into dead body parts.” 

“THAT’S TWISTED!!!” Taiju screamed as he looked at the mad scientist who twirled the miracle water around. 

“I’d grown attacked to all of them, so thought I’d a least test it out on them first, but as expected, it won’t be bale to save anyone that’s already dead. They’re precious sacrifices to our future…” Senku thoughtfully looked at the bottle. “We should say a prayer for them.” 

“RIGHT!!!” Taiju clapped his hands together and started praying. “Ashes, to ashes, dust to dust…” 

Afterwards both of the boys climbed up the tree and got prepared to revive Yuzuriha from her stone prison. But before Senku could pour the nitric acid on her Taiju hastily turned around. 

“WAIT! SENKU!” 

“!?” 

Taiju stabbed Senku’s eyeballs with his fingers and knocked him back on to the ground. 

“Yuzuriha is naked!!!! We can’t revive her like this!!” 

Senku uncovered his eyes and looked at his friend with an unreasonable face. “There you go with another of your stupid, illogical ideas… look around… does it really matter if she’s naked?! This ain’t exactly normal… we’re in the frickin’ stone age here!!”

“It does matter!!” Taiju argued back. 

“Seriously?! Who cared if you’re flashing your bare ass or waving your dick around for the world to see?!” 

“YUZURIHA DOESN’T HAVE A DICK!!”

“THAT’S NOT THE POINT.” 

“I’m gonna bring her back to our cap and dress her in clothes.” Taiju lifts her over his head and prepares to walk back to their camp. 

“Huh? Seriously… how many kilos does that statue weight?” 

“Yuzuriha isn’t fat! She’s not even chubby!!”

“Again, that’s not the point.” Senku, completely done with the situation, retorts. 

But before they could start to make their way back to their camp Senku heard leaves rustling. 

“Wait!! Big oaf!”

Both of them turn to the over side of the clearance and see two wild, predator eyes looking back at them. Without hesitation, both of them start to run for their lives. 

“What the fuck?! WHat the hell is that… in Japan?!” 

“The only place that could have come from is the zoo! It’s keepers must have gotten turned to stone while its gate was open!!” 

Both of them scream as they run back into the woods, running at full speed with Yuzuriha still in Taiju’s arms. 

“Without any humans around, it was free to escape. And withing the zoo everything is its prey. And once it gets loose on the town, it’s got an all-you-can-eat Buffet of everyone’s pets.” Senku continues to explain as they run. “So just as its namesake suggests, it’s the King of the beasts now! Now that 3700 years have passed in this stone world… this means humans beings are no longer at the top of the food chain ..!” Senku screams the last part as the Lion gets closer.

“But why have the lions never attacked us until now?” 

“Kukuku.. If you put yourself in their shoes looking at us… it’s the first time they’ve ever seen a bipedal being.” 

“Oh, I get it… Since there haven’t been any humans…”

“They were being cautious, on the lookout…” Senku pants as his stamina comes to its limits, but he kept going as adrenaline flowed through his bloodstream. “But it was just a matter of time. Our only option is to get back to the camp and utilize the Phalanx (Spear wall). Of course, that’s if we can make it there. This game’s just barely started, and they’ve already got us in check!!”

Before Senku could continue he got Yuzuriha’s statue thrown his way and barely caught her before he met with the floor with her figure in his arms. 

“Scientific knowledge is the final stronghold of humanity! You above all else musn’t be allowed to die, Senku!! So if it come down to it, I’ll be your shield!” 

“NO!” Senku interrupted and stood behind him “Your strength lies in physical stamina and endurance, not fighting ability. Ever since elementary school, you’ve never hit anyone even once!” 

Senku had always seen how Taiju had protected him and his projects from older kids who where jealous about his inventions. But neither him or his project got hurt because Taiju always stood with him for protection. 

“Think about it logically! I use my brain, you use your body. We can’t make it with just one of us. If you think about it logically… when it come time to run…. It’s got to be both of us together!” 

“You’re right!! 

After finally having gone through Taiju’s thick head both of them start to run again. Senku was slowly but surely coming to his end as they continued to run. 

And before they knew it they neared a cliff and without hesitation Senku concluded that it was the best escape route, even if it was just to give them a few moments of a head start. Both of them jumped and before they met the ground a few vines caught them. Neither of them were long in the air as the vines snapped under their weight and send them back on the ground. Without a pause they stood up and continued to run, this time Taiju went ahead. 

“This way! I found him on my first day. The strongest High school primate…” The stopped in front another tree were a intimidating person sat. muscles bulging, hair cascading down and blocking his face. “Shishiou Tsukasa!!” 

“Sorry, Yuzuriha! But right now, what we need more than anything is someone that can fight! If we’re able to beat these lions, then I swear you’ll be next..” 

Before Taiju could start with his nervous ramble and waste more time than they had already wasted, Senku handed him the miracle fluid. 

“Just hurry up and pur this stuff on him already, you great big oaf!”

Not a second later after Taiju poured the fluid on Tsukasa, the lions started to surround them. 

“Oh shit!!!” 

The sound of air came form behind them as the stones slowly broke of from his body. The fragment of the stone fell from Tsukasa’s eye to let him see what was happening. 

 “Sorry! For waking you after thousands of years… into a situation you know nothing about…” 

“What’s the current situation?” he asked calmly and with a commanding voice. 

For a second Senku was shocked when he heard him speak like that before he got back to his bearing.
“Your entire body is surrounded by some kind of mineral substance. We’re surrounded by a pack of lions from 9 to 2.” 

“Okay.” Without hesitation his broke all the stone fragments from his body with one move an fred himself from his imprisonment. And he used the remaining fragments around his arms to shoot them against the lions and some also hit Taiju while Senku had lied on the ground from the moment Tsukasa had stood up. 

Tsukasa didn’t pause for a moment and immediately jumped into action and punched the leader of the lions with his fist, killing him instantly. Both Taiju and Senku were left stunned at the power behind his punch.

“As far as what’s going on you can take your time in filling m in on the details… But I promise you this one thing!” Tsukasa walked to the dead lion while talking to them “That from noe on, n threat or danger will ever again be able to visit upon you… Because from now on, they’ll have to tangle with me!!”  

“HEEEEELLLLLL YEAAAAAAH!!!! Frickin’ awesome, Senku!! Now humanity has brains! Brawn! And Battle! The three Musketeers have all assembled!!” 

“Kukukuk… I suppose so though at this stage, we don’t have muskets… or swords, even.” Senku sweatdrops as he looks towards Tsukasa “But still, this guy Shishio… you could almost say he’s too strong.” 

Chapter Text

A lot has happened since Taiju and Senku encountered the lions that survived all those years without their caretakers and since they had no choice but to free Tsukasa. 

Tsukasa had saved them from being lion lunch that day and killed the alpha lion from the pack. The rest of the lions ran away after seeing the immense brute force behind Tsukasa's fist. Over the thousand years when humanity got covered in stone and no one walked the earth, letting mother nature take her course and recovering everything in greenery and nature, the lions had retaken their rightful place as the kings of the foodchain. But now after having seen the first bipedal animals and seeing what strength they have, made them cower and rethink their position in the world food chain for terrestrial animals. 

After scaring them away, with the help of the strongest high schooler Tsukasa, did the trio walk back to their place with lion skin and meat. Senku had explained to Taiju that the meat was edible but reeked of ammonia and was tough but they still ate it for dinner that day. 

Over the course of days did the trio get to know each other better and hunted and created more stuff for their survival. They worked fast and Tuskasa provided them with enough fish and meat for them to live without a problem while they thought on what to do next. 

“Ooooh, I see!!! We grill them as soon as we catch them! That way even without a fridge, they won’t go bad!!” Taiju cheered when he saw Senku hanging when over the fire. 

“I’m not grilling them by using the aldehydes of the smoke, I’m killing off all the microbes in the fish. But to put it in a way that eve ou simple mind can understand, I’m smoking them.”

“With Senkuu and me working together we won’t have to worry about food preservation.” 

“Yeah… at least we’ve taken our first step towards civilisation.” 

“Wait… does that mean we were still at zero?!” 

Senku chuckled and turned to them with his signature smirk. “And now it’s time for a fun little quiz. If we want a scientific civilisation… what’s the most important thing we need first? The correct answer gets ten billion points.” 

After a lecturing Taiju and getting a pretty close answer from Tsukasa, Senku revealed what they need. 

“Calcium Carbonate.” The Ishigami siblings said. 

Yuzuki had thought about it on her journey, walking on a beach and collecting seashells. 

“This is pretty handy, four things can be made with Calcium carbonate.” she hummed as she crushed them on a big falt stone and collected the now dust from the seashells. “I do need soap, hygiene is my biggest priority. If not I can say bye bye.” 

Fast forwards to the trio of boys, Tiaju was shouting as per usual. 

“I see! As usual, I haven’t got a clue what you’re talking about!”

“You mean, Lime?” 

“That’s right. Let me try to explain it in a way that  even simple-minded moron over there can understand. It’s the stuff they use to draw out white lines on sports fields.” 

“Big oath. These are the shells that have played such an important part in caring for your facial hair. Simply by smashing these to pieces… BOOM! You get calcium carbonate, just like that!” 

“A little survival knowledge, Onee-san taught me early on.” 

“ALRIIIIIGHT! IF IT’S PHYSICAL LABOR, I’M IN CHARGE! JUST LEAVE IT TO ME!”

“Kukuku… there’s nothing that excites me quite like calcium carbonate. It has four uses so important, our very lives depend on it.”

“Use one! Agriculture!” The Ishigami siblings say, one explaining everything to his group while the other one is collecting her stash of seashells on the beach she is months before Senku starts to work with them. 

“By ussing lime we can neutralize  the hydgrigen ions from the soil! In other words, we level up our soil big time!” Senku informs. 

 “Two! Mortar!”

“By mixing it with sand and roasting it over a fire, we can create Mortar. It’s a child of cement. Which means we can build large stoves, furnaces, and even houses.” 

“Three! Soap!” 

“In this world, Sickness = game over. This tiny little lump here which can purify and kill germs. Will be out stone of life in place of a doctor… DR. STONE!”

“I’ve never seen anyone as sharp, smart, or quick-witted as you. I respect you, from the very bottom of my heart.” 

Senku stopped his movement as he peered at Tsukasa. “A man who flattered another man to his face is either a homo, or a conman. So what is it you’re trying to say.”

“You wound me. I don’t have any particular intent in saying it. All I mean is that you of all people might truly end up creating a modern civilisation from zero. Mmm. That’s all I was thinking.”

But before Senku could dig deeper on what Tsukasa was really thinking they got interrupted by Taiju who came back with a new load of seashells he was collecting the whole time. 

“Well! What’s the fourth one? You said that there were four, right? Four important uses for shells?” 

“No. theres three. I said three, didn’t I?” Senku blankly stared at Taiju. 

“Wahaha, Oh, really? I guess my memory's pretty crude and simple too!!!” 

“And four. Gunpowder. But I don’t need that right now. Even though it would come in handy at some point probably, but bow and arrow are sufficient for now too.” Yuzuki wiped the sweat from her face with the back of her hand.  

Senku already had his hunch that something was going to happen with what Tsukasa had said previously to him about the moder civilisation and didn’t want to further tell him any of his knowledge and ideas about what he could do and what the fourth thing what seashells could create. He hoped, which e was a billion percent sure wouldn’t happen, that Tsukasa wouldn’t act to early. 

But this change quickly, while Taiju was busy collecting seashells until the sun went down for Senku, who was contemplating where his sister is and how to continue with everything, he saw Tsukasa in the water next to a statue with his spear in hand holding a seashell. 

Tsukasa told him a story about how the world was a corrupt place and that they had the opportunity to make it a better place for the younger generation if they took care about who they freed and who they leave caged in stone. 

Tsukasa showed Senku who he really was. Senku already knew that something was not right and kept his guard up, but after hearing Tsukasa talk about a better world did Senku only realise how bad it really was. A shudder ran down his spine, even though he would never admit that he was slightly affected. He started planning on how to stop the inevitable, how to prevent Tsukasa to break more and more statues without killing him. Killing was something that Senku never planned on doing, even if it would be the easiest solution, but everyone has a right and everyone has the right to walk this earth even if everyone can be a threat to others. 

Morals are what society may not be built on but morals are what makes people. People. 

Setting his boundaries and morals was probably one of the many things he learned besides science and the stars. Even when he sometimes is a anomaly for people when they thing of morality but taking a human life when he can prevent them for dying is still something he liked to avoid. His family wouldn’t be very happy if he deliberately kill someone, especially a specific someone who watched him grow up apart from his sister and father. 

He may or may not have sacrificed a humans arm when he tested the nitric acid, or how Taiju liked to call it, miracle water, but it did not mean that he would kill off Tsukasa just because it would make everything easier. He can just think of a way for preventing Tsukasa of knowing the formula. And after he gets Yuzuriha free, he can think of another way to piece all those statues back together. 

As much as he wanted to do that he could immediately scratch the first thing of his list because the big oath made his job way harder than it already was. Fighting a fighter like Tsukasa was already hard. Especially because Tsukasa wasn’t only muscle but he also had brains. It wasn’t easy to fool him like Senku can do it sometimes with Taiju or tell him to just not worry about it. 

Tsukasa knowing where the cave is, was already something he could live with. Even when it’s a big gamble. The moment Tsukasa had left the camp, Senku got to work and prepared the fluid for freeing Yuzuriha and prepared to leave, giving his friends a choice on what they wanted to do next. 

After both of them had made a decision and Tsukasa had temporarily left after the first assault their journey began to walk all the way to Hakone where Senku would be making gunpowder for them. Because in order to survive a fight against Tsukasa, gunpowder would be their best bet. 

After escaping without a problem and Tsukasa on hot pursued to catch up to them they arrived without a problem at Mount Hakone and the hot springs after they saw the buddha statue still standing. The statue was the Landmark in Kamakura,The bronze statue of the great Buddah in Kamakura, with that Senku knew exactly where they were at that moment. 

“Ku..kuku.. Now I know our location.. 35 °19’ North… 139°32’ East..!”

After walking the distance of two Marathons, 80km, they finally arrived at the top of Mount Hakone, A Vulkano where the hot springs reside. 

“We’ve made it to our goal!!” Taiju sprung up in happiness “Hot Springs!!” 

Yuzuriha and Taiju had not problem when they arrived at the top, but after walking endlessly and hiking up to the top, Senku had arrived at his limits a long time ago and dragged himself with the last strength he could muster up the Vulkano. 

After relaxing in the Hot spring, Senku immediately went to work and chipped off some Sulphur from the hot spring to make GUnpowder with the help of Yuzuriha. They had everything they needed but after stomping every single ingredient together with the help of a stone and Taiju’s strength, Senku forgot that the Vulkano can light a explosion and they where able to ran far enough to not loose any limbs or worse their life. 

Apart from nearly loosing their life they had successfully created gunpowder, but they had also lighten up a fire that gave away their position when the explosion released dark smoke. But not only did they made Tsukasa speed up his pursued, they had also let two other people know that they were on top of that Vulkano.

“An explosion, in this age?” Yuzuki looked up and saw black smoke further away as she came to a stop. “That position, that should be mount Hakone. But the only other person I know that knows the ingredients would be…” Yuzuki placed her finger under her chin as she looked up. “Senku.” she smiled and continued on her way. She was pretty far from their position, it would take some time until she even reached them, but that wasn’t ehr concern right now, she would search for her brother when she neared Hakone. 

While the trio looked on the other side of were Tsukasa was, they noticed another fire as smoke drifted up into the air. Senku was stunned when he saw that. Pressured by the decision on what to do next, if he should light up the fire or not. But in the end they took their chances and threw more wood into their fire to keep the signal going for the person that answered their smoke signal. 

Shortly after a lot had happened. Tsukasa took Yuzuriha as a hostage and threatened Senku with her live. He took Senkt out when he didn't agree to give up on science and in the end Taiju and Yuzuriha ran away with Senku to keep him and their live safe after distracting Tsukasa. It rained as they mourned for Senkus live and tried to save him. Yuzuriha realised that Senku had always indicating something that was on his neck and they saw a piece of stone still stuck there and put some miracle fluid on it and hoped that it would wake him up. 

In the end Senku woke back up but was nearly crushed by Taiju and his hug. Yuzuriha got a plan from Senku when he knew what had happened and gave her an order while they were going to Tsukasa and stay with him. Meanwhile Senku would go and search for the person who had made a smoke signal. He was curious who they are and if there were more people he could use for the help to rebuild modern civilisation. 

After separating from each other Senku made it his goal to find this person which was pretty easy because Tsukasa came across this person and made them stuck under a tree. The moment Senku found this person he got to work and built a pulley and freed the female he had found from under the tree. 

Since then Senku met Kohaku, she let him to her village. The moment he saw it he knew that he could come up with a new plan and defeat Tsukasa when the time came with all the man power he would gather in that village. 

But before he could do that he would need to know how everything works and how the minds work from these people. Senku had quickly realised after meeting Kohaku that she and her people didn’t get petrified by the green light but were people that had survived and lived all those years alone. 

So Senku’s next goal was to see on which smartness level they would be which got tested the moment he and Koahaku neared the bridge and got stopped by the guards, Ginro and Kinro. Not only did he gather the information that they were scared of Koharku, one hiding it better than the other. Not only that but he also realised that their IQ was pretty primitive and sweatdropped when he realised with what he had to work with. 

But at least he found at least one person that was interested in the world enough to keep science alive even if Chrome named himself a sorcerer. After witnessing Chromes rainbow bridge and sulfur ball, that at least peaked Senku’s interest at least a little bit, Sennku walked into Chromes hut and saw his whole collection. 

“Kukuku, feast your eyes on this Tsukasa. You may try to kill me or anyone else… In ou effort to rest science but from we smooth, shiny monkeys. Another crazy idiot who wants to experiment with anything and everything…will always  rise again! Scientific civilisation will always rise again!!!” 

Senku glanced at Chrome as the boy talked about how he got to his collection. With everything he saw he was sure to want Chrome on his team so he gave Chrome not a real choice at least and told him to join his Kingdom of science. 

“Lemme tell you something, Chrome. At this rate you’re one of 10 billion percent sure to be killed by Tsukasa. Your only choice is to join my Kingdom of science.” 

Chrome was sweating at the verbal attack on his life and stood there confused, but he snapped out of it quickly when he saw what Senku was about to do and shouted at him. He tried to safe himself and his collection one last time and thought he would for sure win if he challenged Senku to a Arithmetic duel. On the side line Kohaku didn’t had so much faith in Chrome and had the bad feeling that Chrome would loose that Duel too. 

While Chrome had lost the duel his sprit soon uplifted again when he realised that Senku had the same eager passion when he looked at his stones. Meanwhile Kohaku left quickly, she couldn’t handle their spirit as they goofed off on some rocks and she didn’t see the appeal to them. 

Senku quickly tried to get Kinro on his side with a golden spear, but failed for the time being, which only seemed on the surface. Senku was able to get Kinro and Ginro on board fairly easy. Afterwards, Senku found Chrome’s plants nad herbs. 

“You’ve got plants and herbs, too? Alderfly, daylily, canker root.. Hang on… these are all traditional chinese medicinal herbs… These are medicines!” 

Chrome looked melancholic as he told Senku the reason behind his plants and herbal collection. 

“Yeah. Although I was never quite sure if they would work or not. I was the only one crazy enough to test them out, so I had to try them on myself. If i can somehow heal Ruri’s illness.. I’ll collect anything I have to. That’s the reason why I became a sorcerer!”

Chrome shouted Senku’s name when he remembered that Senku’s was smarter than he was and knew more. 

“SENKU!! Isn’t there any sorcery… err, I mean science that can save Ruri?!” 

“I won’t know until I see her. There is a kind of cure-all that exists… But we don’t have everything we need to make it.”

“This would be easier if Onee-san was here…” Senku frowned when he thought about making medicine for this Ruri. He knew that his sister could make it faster and way better than he could or she could even find a way to make the route for it a little easier for them. 

“CHrome for now I should tell you everything. All about what the world was like 3700 years ago. Before it got destroyed.” 

And with that Senku sat down with Chrome and told him everything that got discovered over the years and every invention that made the market, how everyone travelled around, lived, how communication functioned. About the first airplane, they first man on the moon and how science was able to help the people. All the basic were covered by Senku that day and afterwards he answered every question Chrome had. Senku had a little sympathy with Chrome when he saw how devastated he was even though he didn’t even exist in that time. 

 “Kukukuku… it wasn’t completely wiped out, moron. In fact, it’s still well and intact.”

“WHERE?!” 

“Humanity won’t lose that easily, right now the humanity of 2.000.000 years ago every last bit of it.” Senku points at his own head as he looked Chrome deep into his eyes “Is in me, right here.” 

Senku’s fist also came in contact with Chrome’s chest “And in you, too! Am I right?!” 

“I’m going to build up a country of science together with you! And I’m gonna make a crazy effective medicine and stamp out Ruri’s illness!!”  Chrome declared.

Chapter Text

Ishigami Senku had his first member of the science kingdom join him on his quest on reestablishing science to the current world. In the end Kohaku joined the mad scientist and his crazy partner to make a cure for her sister. 

After going over the tow routes that could get Kohaku’s sister back to health. 

“The biological route would be preferable, but judging by our resources. sigh guess the stone route it is.” Senku was exhausted after having to explain all about the past and drawing all those different route plans. Though he knew that that it was visually better to understand for those two so he didn’t complain. 

Senku was picking at his ear with his pinky when they walked to the river to collect iron, all clothed in swim wear. 

“This would be a billions times easier if she was here…”  

After collecting all the iron they could find for the time being they went back to their camp with an additional member for their kingdom. 

Hours later they all lied exhausted on the flour as the sun was setting they all realised a crucial detail that they needed to fix quickly if they wanted to achieve their goals. 

They needed man power. 

And what better way than to multiply their numbers. 

Food. Everyone would like food. Especially fi it was something that they ever had. 

After finding foxtail, Senku started to prepare his favourite dish. 

Ramen. 

After a taste trial it seems that everyone would love it, even though Senku had other thoughts about it. 

Disgust. 

“Well as long as the others like it. But ti seems plausible, they had never eaten anything like this.”  

He shook his head but decided that it would work for the time being. He would make a better version later. Though he had a sense of deja vu when he looked at the three. 

Later they started to build a small cart to sell the dish. Senku was preparing each bowl for the villagers while Suika was standing on top of it and playing to get the attention of the villagers. 

“With science’s gourmet this green foxtail ramen. We’ll be able to gather the kingdom of science’s villagers we need to create iron!!!” 

More and more arrived and tasted the new invented dish, well new invented for them. Gulps of anticipations and stares of curiosity were thrown towards the bowl as Senku presents the dish to the villagers. 

“It’s so springy.. chewy … and amazing!! It’s just… unbelievable!!” 

“Fufufu well, if Gannen, the man who for gluttony says so… then it must be good right?” 

“So you’re the person who made this incredibly tasty dish.. <3” Ruby says passionately. “Your name is Senku? So… what kinda girl is your type?”  

“The kind of girl that can bring me tons of materials for Iron making.” Senku said without hesitation while grinning widely. 

“You’re way too straight forward!!! Senku.. Your seriously don’t beat around the bush in the least, do you…” 

The bizarre dish made them sceptic but also intrigued and curios so they all ate from it with the expectation fo the guards. 

“Come on Kinro, Ginro! This ramen stuff is seriously crazy!”  Kinro and Ginro still stood at the bridge when Chrome neared the two guards with two bowls of ramen. 

Ginro wanted to really eat it but Kinro forbid it. So Ginro had could do nothing but look at everyone eating while saliva was dripping down from his mouth. Though the moment Chrome came over, Ginro couldn’t hold himself back and jumped towards the two bowls of ramen. Kinro had to grab his collar to stop him from touching them, while Chrome was just standing centimeters away from Ginro’s grasp while laughing wickedly at him. 

“There’s no way we can let that suspicious sorcery food in out mouths! Besides it’s absolutely inexcusable for guards to accept any food! Rules are rules! ” 

Kohaku walked up to the nagging Kinro and reminded him about a little detail he might have forgotten. 

“Ohh, then what about that fold spear? Food is a no-no, but you’ll take offerings?” 

“Yeah, that’s right!!!” 

Kinro could do nothing but look at both of them and trying to somehow make his way out of this conversation. 

“Hey, if you take too long the noddles are gonna get soggy!!” Chrome tried to get their attention back to the food he holds in his hands. 

“How many bowls is that?” Suiksa was in disbelief as she watched the gluten of the village continue to down bowl after bowl. 

Everyone was having fun and a good time as they ate. Meanwhile Senku was trying to keep up with all the cooking until something had caught his ears. 

“This seriously makes me wish I had something to drink~ like a cola…” 

“Cola?!!” 

Kohaku caught Senku’s change. “Is that one of your friends, Senku?” 

“No” 

“Kinro, Ginro, sorry to break up your argument”

“What’s wrong…?” Kohaku’s change of attitude caught Kinro’s attention. She normally would let them continue and doesn’t really care, but this behaviour indicated that something was wrong. 

“I’ll keep the explanation short and to the point.” She went closer to them and lowers her voice. “An intruder.” 

With that word all three of them went into action and jumped towards the stranger that was sitting behind a bolder near them. All their weapons froze a few centimeters away from the strangers neck. 

The intruder held a bowl of ramen in his hands as he stood were, his hair was dual coloured while he wore a traditional styled clothes and no shoes. If you looked close he had a subtle smirk which he covered up quickly to not get caught, but over than that no one could see how this person was feeling right now. His body doesn’t show anything, no fear, no anticipation, no agitation, nothing. 

“Answer truthfully. Don’t even think about lying or I’ll cut your throat open right here and now.” Kohaku started her interrogation. “Are you one of that long haired man’s people?” 

“WIth Kohaku on our side here… I don’t have to be afraid…. I can act cool and tough all I want!”  Ginro was shaking lightly, trying to not show is fear while he held his spear near the intruder. 

“Mmmmm~ GGetting tied up by a girl cutie like you might not be so bad at all… But I think you’re mistaking me for someone else.” The dual coloured man raises his head slowly and a look of mock confusion appeared on his face. “I have no idea who this long haired man is. Ever since I broke free from the stone I’ve been all on my own…”  

After he raised his head, Senku was able to get a better look at the mans face and realised where he had seen his face before. It reminded him, back in High school one of his classmate had a magazine with questionnaire inside, ‘who would you safe when they’re in danger.’ or something like that. The only think he remembers is that the questionnaire was complete bullshit, so were his magic shows that ran on television. 

“Nee-san has the tv on in the background. Sometimes the channel would show his magic shows.” a little smirk appeared on his lips. “Full of garbage like his books.”  

“I thought I#d seen your face somewhere before. Asagiri Gen!” 

“An acquaintance of yours?” 

“Not even for 1mm. He’s a magician that writes these garbage psychology books.” 

“Oh, you’ve read them? I’m happy to hear that~ But garbage? That’s pretty harsh… And please, call me a mentalist.” Gen smile innocently as he looked towards the leek haired guy. “Anyway, I apologise for Indulging in your ramen all on my own. Now would you please lower your weapons? I’m so scared I’m shaking all over here. I might end up spilling this ramen you worked so hard to make.” Gen faked a nervous look as he handed over the bowl to Ginro who accepted it with open arms. 

“I’ll– I’ll take it off your hands!” 

“It’s all complete bullshit. He’s not trembling in the slightest.” 

“The words that come out of his mouth are like feathers. Completely light and weightless…!!” 

“There I was, out searching for food today.. Whe Imagine my surprise! The nostalgic smell of ramen came wafting through the air~!” 

Senku didn’t belief the mentalist a single word as he wordlessly watched his show. But after seeing that the mentalist was finished a evil laugh left Senku as he stembed his hand on his hips. 

“Kukuku, well if that’s the case, then we’ll let him be. Besides, there’s not such thing in the world as a free meal. Everyone ho ate any ramen will have to work!” Senku, always the opportunist, knew he could take this to his advantage. 

“Work?” Gen looked dumbfounded. 

“You mean like washing dishes?” 

After collecting everything, Senku took the lead and led them back to the hut where their construction stood. All of them stood at two of the new air pumps and worked to their limits while steam came out on the top and all the air vents. 

“We’ve upgraded the Huff-Puff device to power it up! Now our Iron-making ability has gone to level 2!” Chrome screamed at them, explaining how those devices worked. 

“We could actually manage this if we work in shifts…!!” Kohaku added as she pumped. 

Meanwhile Senku walked closer to the mentalist taking the opportunity to get a few informations out of him. “Asagiri Gen, How are Taiju and Yuzuriha doing?” 

“Ah~ So that’s what you were after. You thought if you world me hard to the one, I’d end up slipping up in my desperation. You’ve got some real guts. You really think you can take on a mentalist in that kind of fight? But don’t worry.” Gen looked over his shoulder and smirked evilly at the scientist. “They’re fir as fiddles. Especially that Taiju with his bottomless stamina! As I’m sure you know….Senku…” 

“So he’s one of Tsukasa’s men?!” 

“Wait, dummy. Asagiri, Gen.. I was already 1 Billion percent aware that you were playing coy just to gain information. But why would you suddenly come out and admit  that you’re one of Tsukasa’s men?” 

“....Because the situation has changed. After I saw this.” 

Everyone worked throughout the night until the next morning arrived. Senku was clothed in thick lever and took out the bowl of liquid iron out of the fire and filled it into a form. Gen stood with everyone else and couldn’t belief his eyes when he saw the Iron filling the form. 

“If I can be blunt… I was sure that if we fought, 10 out of 10 times, Tsukasa’s empire would win.” 

“Indeed.” Senku didn’t deny it, he was already aware that he couldn’t fight against someone who had more than a million times of muscle power than he has. Not only was Tsukasa strong, but that guy was also smart and that made Senku job even harder. 

“My job is to confirm your death, Senku.All I’d need to do is say “Tsukasa! Senku’s alive!” and it’d be the end for you. And that’s what I had planned to do.”  Gen lifted his hands and shrugged nonchalantly.  “But if you’re able to create iron weapons then who knows how the outcome of that fight turn out!!! All I’d need to do s give him a false report. “All I found was a primitive settlement. Senku is dead.” And then you’d be saved.” 

“Kukuku~ Well, I guess I’d be pretty thankful if you’d do that.” 

“I’ve for no policies, morals, or hang-ups at all! The world’s most silver-tongued man!” Gen exclaimed proudly “All I want in life is to shack up with some cute little girls and enjoy myself! I could care less whether you or Tsukasa die. No matter which one of you falls, I’ll be riding the winning horse! But I’m pretty torn here should I betray Tsukasa and ally myself with you, little Senku? Tsukasa’s Empire vs. The Kingdom of Science.. Which will win~?” 

“What? It’s obvious isn't it? The Kingdom of science!” 

Senku had thrown his protection gear away and wanted to say exactly those words but got stopped when they heard a feminine voice said them instead. Everyone who was still there tensed up and waited for the person to show themselves. Only Senku tensed up for a different reason and looked over Gen’s shoulder. There, between the trees. Senku couldn’t belief his eyes and ears, without showing an ounce of emotion and keeping calm compared to the others, he walked closer. 

“Kukukuku, you late.” Senku stuck his pinky into his ear as the person walked under the sun. “What took you so long.” 

A woman walked out with a bag slung over her shoulder, her hair was white and into a low, loose bun. A few pieces a hair frame her face, in her hair there was a wooden stick that kept her hair together. She wore loose pants, on top she for a fitted white top with long sleeves that covered her most of her neck, on top of that she wore wore a loose light blue wide sleeves that were tight with some bandages at her wrist to keep them in place, there were also tucked into her trousers. Her clothes mainly consisted on beige and blue colours. 

The villagers were confused but didn’t intervene or pretest like they did when Gen uncovered his presence to the others. This time it was different as Senku knew this person and walked up to her. Of course they were still tense as they didn’t know who that was. Kohaku walked a little closer to make sure that nothing would happen to Senku and placed a hand on the her knife. 

Gen on the other hand had turned around when Senku walked pass him. His eyes went wide when he saw her. 

“Who is that? She is so beautiful…”  Gen’s mouth was wide open, Chrome had a similar reaction when he saw the woman. 

“She is so pretty… just like Ruri…” 

“I though I would let you work on your own for now.” 

“Well, you could have come earlier.” Senku contered annoyed when he saw her small smirk. 

“Why? And let you slack of?” She chuckled “I thought you don’t want my help?” 

“That was 3689 years ago.” Senku gritted his teeth, “ sigh It doesn’t matter. You are here now I guess.” he dropped the banter for now and scratched his neck. She just chuckled softly as he turned around. 

“Eh, Senku. Who is that?” Kohaku neared carefully, still on high alert. 

“Mm, oh yeah. That Yuzuki, my sister.” 

Senku was walking towards the hut to continue with his project and dragged his sister with him by her wrist. He knew she would follow him if he indigated it to her but he wanted her opinion about the herbs in the hut. Yuzuki wasn’t resisting at all and just followed him without a complain. Everyone else stood at a daze as the Ishigami siblings walked past them. 

Gen on the other hand snapped out of his daze quickly and continued with his speech, hoping to get a reaction out of the scientist. 

“Little Senku vs little Tsukasa! Which one would benefit me more if they win? That’s all I care about.” 

“Since when did you have that mentalist in your team.” Yuzuki moved closer and whispered to Senku, completely ignoring the mentalist. 

“Believe me, I didn’t invite him.” He gave her deadpan look. 

“Your name was Asagiri Gen was it? Well… A selfish, flimsy, thin willed worthless man like you, I think I’m better off just killing you, at the least, locking you up.” 

“YIIIIIIKEES!!!” 

“If we don’t let him go back to Tsukasa’s then Tsukasa will come check on him himself!” Senku was starting to get annoyed as he climbed up the ladder to the hut. Yuzuki was already waiting above as she looked around at all the materials. Picking up herbs and studying them, waiting for her brother.

“Kukuku, Don’t worry. Once you see what I’m about to make out of my amazing new item, iron…” he smirked towards Gen with a confident look. “You’ll 10 Billion percent want to joi the Kingdom of Science.” 

“Hmmm~? And what will it be? A Katana or something?” 

“Probably something with electricity. A power station?” Yuzuki was mumbling to herself as she looked through all the herbs. 

“A power station.” 

Gen was dumbfounded when he heard Senku said he wanted to built a power station. 

“Wait. here?! In the stone world?! Are you nuts?!” Gen was now started to sweat profoundly. “That’s just way too impossible!!” 

“Wow, you’ve even got some copper in here?” Senku completely ignored Gen’s nervous breakdown as he talked with Chrome as he looked through the mineral pile. 

“Yeah, but it’s pretty so i don’t want to break it!” 

“We’ll melt it and turn it into copper wire.”

“Are you listening, goddamnit?!” Chrome whined, still standing on the ladder. 

Yuzuki chuckled at their exchange as she watched them and looking though all the minerals, searching for additional material that could help with building the power station. 

“After that… We just need some lightning to come…” 

Immediately after the words left Senku’s mouth, lightning appeared in the sky.

“You jinxed it, imoto.” Yuzuki looked towards the shocked Senku while everyone else was fascinated and shocked at the same time. 

Rain started to pour down as everyone looked up. 

“It really did come…!” 

“Ah! Well, it is lightning season!” 

“We’re seriously lucky!” 

“Not really…” Yuzuki laughed weakly and walked to the hut to start with the preparations. 

“No! It’s completely the other way around! This is the absolute worst! We’re not even a millimeter ready yet!” Senku shouted at everyone. 

The remaining villagers ran back to the village. The village was screaming as they ran for their houses. 

“The ‘sky’s anger’ lightning has come!!!” 

“If it hits you, you’re dead!!!” 

“Get all the women and children into the houses!!”

Gen and Yuzuki watched the commotion. 

“The possibility that anyone would get hit is less a million, and not even 10% of those die by it.” She mumbled as she watched the chaos unfold in the village. 

“Don’t tell me you’re making a lightning generator?” Gen turned towards Senku. 

“That doesn’t exist.” Senku replied bluntly. 

“I didn’t think so~” Gen had his hands together under his rope as he watched Senku work. 

“If we have a Magnet. We can create a Dynamo… A power generator.” 

“If you need a magnet. What abut the ones we used to collect iron sand?” Suika hel up the small magnet stone that they had used. 

“Natural ones aren’t strong enough for what we want to achieve.” Yuzuki said softly as she looked at the girl. 

“We’ll use the power of science, have lightning strike and iron bar and create our own high powered magnet!!” Senku held the magent stone in his hands and looked up “I had planned to put up an absurd number of lightning rods and wait…But I can’t let this chance slip by! We’ll make preparations as fast as we can! That’s right… We’ll literally work at Lightning Speed ”

Everyone worked at the Ishigami’s instruction and got everything ready, even Suika ran back to the village and borrowed a bottle Lacquer from one of the villagers. Her speed had shocked Gen who was standing near the bridge at that time when she zoomed past him. 

“Lacquer possesses some serious insulating properties! Coat the ron bar with it!” 

“Wh… what is this…?!” 

Senku went to the bridge afterwards and ripped out a blank from it and carried it back to Kohaku who carved a groove into it. 

“Wah! What are you doing with a board from the bridge?!” 

“You sure it’s ok to just take the blank?” Yuzuki sweatdropped when he walked past her towards the lioness who carved the groove. 

“Yeah, yeah. It’s fine, it’s not like we are using it to make a fire or anything.” 

Yuzuki couldn’t help but shake her head as she closed the bottle of Lacquer and walked to Suika. 

“All I need to do is carve  groove all over this board.”

“Now we pour the copper into the groove. Wait until the copper wire hardens and wrap it around the iron bar.”

Everything went smoothly, until the unexpectant happened. Magma, the village strongest and selfish’s man walked towards them. He and his followers were walking towards them, believing that they had angered the sky with their sorceries. 

“Just leave it to me. I’ll kill them.” 

“Aw crap! It’s Magma!” Chrome panicked. 

“Words won’t get through to a man like him. We won’t be able to avoid a fight!!” 

“If we get into an all-out fight with the village now, it’s all over! Damn it.. We’ve got to do something!” 

“Hmmmmm~! I guess I con’t have a choice. I don’t wanna get killed too if I get caught up in this.” Gen looked at the scene before turning to Suika who was standing next to Yuzuki. “Would you mind handing me a bunch of flowers, Suika? Flowers are much better than a war, after all…” 

Gen walked towards the bridge and presented the brutes his flowers as he showed a very happy, go lucky expression. 

“What the hell are you doin’ bringing out flowers to us, you fruity pretentious prick?!” 

“Were you the one that called the sky’s anger here?! Muhahahahah! You’ve got some guts coming out here on your own just to be killed!” 

“Ohhh, You#ve got it all wrong~ We have come here because of the lightning… But using sorcery, we’re going to make it disappear!”

“A very likely story! It’s all a bluff…” 

“Just like this!” Gen showed them the flowers again before flipping his hand, only his palm visible, letting the flowers disappear from their sight. 

“They really vanished…!!! Right in front of our eyes!!! Impossible!!” All three of them looked in disbelief as they watched Gen’s magic trick. 

“...I wonder if from where they’re standing… Magma and the others can’t see that!” 

“It’s a technique known as a backpalm. Kukuku… not bad, you scam-artist magician..!” 

“Why did I had a feeling he would do that exactly that.” Yuzuki shook her head as she watched on. 

After Gen scared of the potential threat they made their way up to the highest spot near them so the lightning would be able to strike at their iron. Senku was exhausted before they even made it halfway up the mountain, so Kohaku dragged him by his collar up as they climbed. Yuzuki had stayed back, she didn’t see the need to follow them and occupied her time with sorting through the collection of herbs in Chrome’s hut and the things she had brought with her, adding here and there a few things in her journal she was carrying around with her. 

Meanwhile the others finally made it to the top of Bald-top mountain as Chrome likes to call it and tried to set up the tower. Kinro and Ginro had followed them to the top and hid behind some bushes to not get caught and observed what they were doing nervously. 

“It looks like they’re building some kind of tower. Should we help…?” 

“Ginro, you bastard.. All you want is a silver spear, right?! Our job is to keep watch over them!! Rules are rules!” 

Senku and Chrome tried to built the tower as fast as possible but the lightning was still faster and caught up to their spot. 

“The lightning is getting closer!!” 

“This is bad!! If we don’t get the lightning rod up on a log or something now.. We won’t make it in time!!” 

“If only we had something long.. That we could plant into the ground…” Kohaku complained but stopped quickly when she looked over her shoulder in search for something. Her eyes lied on Kinro’s spear he was holding and she immediately ran towards it and ripped it out of his grasp with an apology before flipping into the stop and ramming it into the ground and binding the iron bar on with her hair tie. 

Not a second later, when Kohaku flipped away the lightning struck the spear. Different emotions ran through every single one that stood on the mountain top as they watched the lightning struck. 

“Electricity?!!! In this stone world?!” No… way…!!!” Gen mental scale tipped over to the science side by a lot and threw everything off. He stood in shock as he saw Senku’s plan work right in front of him. 

“You can’t be serious, Senku!!! In this completely empty stone world.. Starting from zero. I can’t believe.. You really did it…” 

“The birth of electricity! Now this excites me…!!” 

As fast as the lightning came, as fast did it past. After minutes did the sun shine back through between the clouds. Kohaku was looking at the magnets but got worried. 

“Senku… we may have failed,,, in making these magnets..” 

Senku looked up in shock before his face turned blank. 

“I cant seem to get them close to each other! Some mysterious force keeps pushing them away…!!” He saw Kohaku failing to putting them together. 

“You’ve got the polarities backwards.” 

Senku reached out and turned one of her magnets around but what they didn’t expected was that all three of the magnets they held would immediately pull together. 

“Whoaaaa!!” 

“Waaaaa! Awesome!! They’re so strong!!” 

Powerful magnets acquired!!

“Now we’ll be able to make it, right?! That insane ‘electricity’ stuff?!” 

“But senku.. When you say a power station… will you use.. Fossil fuel-powered generators? Wind powered generators? Surely not nuclear generators?” Gen was sceptical on what was going to happen as their next step. 

“Physical powered generators.” Senku stuck his pinky into his ear. 

“Somehow I figured as much~” Gen could already imagine how tiring that was going to be having traumatic flashback to the air pumping just to achieve iron. 

Back at their base Chrome had filled liquid copper into a round form and waited until it cooled down before pounding it flat with a hammer. 

Meanwhile senku stood near him and told him what to do.

“If we pound the copper into a sheet. We can shave off around the outside and turn it into a disc.” Yuzuki had taken over the spot to mark down where Chrome later on cut. 

“Get a load of this! It’s that crazy hard stone I showed you before! We’ll shave it down with Corundum!” 

“That’s the next hardest stone after Diamond. The Chrome collection pulls through again!” A pufferfish Senku exclaimed. 

“I was considering coating the copper wire in Phosphoric acid originally. The Lacquer’s a little sticky but it works!” 

“Come on, let me do this…” Yuzuki sighed and nudged Senku by his shoulder. He stood up and let her continue with his word in stringing the copper wires through a bowl full of Lacquer. 

“By the way, Senku… I’ve been racking my brain for a while now…And since you’re not going to bring it up, I figure I might as well. Why the hell did you turn into Anpanman?” 

“I’m allergic to Lacquer.” 

“He’s allergic to Lacquer.” 

“I told him to let me do it but he started before I could stop him.” Yuzuki sighed as she continued the work, only briefly looking up. 

They finished with their work when evening fell. In front of them stood the first Senku-electric generator. 

“ALRIIIIIIIGHT!!!” 

“Kukukuku, the Kingdom of Science’s own special double hand-cranked generator is completed!” 

The generator was big, Suika stood next to it and she wasn’t even a fourth as tall as the generator. Yuzuki couldn’t help but chuckled at Suika’s cuteness as she stood next to it and waved her to come to her. 

“We’re going to turn both the discs at the same time That sounds pretty hard.” 

“We can just have two people do it!” Suika suggested. 

“That would still be hard.” Yuzuki chuckled a little, rubbing Suika’s head. 

“If we don’t synchronize and spin it together, it could break and all come apart.” 

“Yeah, if only there were a duo with a lot of stamina and physical skill, and also in totally in tune with each other…” 

“Well we are in synch, but we both lack the stamina and skill we need.” Yuzuki commented, Senku agreed. 

This caught Gen’s attention as he though back to his first day. Everyone looked to the guard brother apart from Suika and Yuzuki. Suika knew who everyone was indicating on but Yuzuki had no idea. 

She just gave a closed eyes smile and waited for what was going to happen next. 

“I could probably built a mechanism that would pull it at a constant speed but it would be too slow for the speed we would need.” Yuzuki thought as she watched the others tried to tempt them to work for them. 

Without a problem the two brothers went to work and in perfect synchronisation too. 

“As expected of brothers, they’re perfectly in sync.” 

“I have never seen someone in perfect synch with another person like them and in that speed.” 

“Oh, I have.” Senku eyed his sister thinking about a person that is in perfect synch with her. “Kukuku.. Kinro and Ginro, acquired!” Senku’s face morphed quickly into a scheming one. “And now we’ve built up a pretty good line-up for the Kingdom of Science!!” 

Later in the evening when they had made sure that everything worked fine, Senku had a bamboo fiber that got roasted and climbed up the hut with two electricity cables. 

“Do we need a high place?” 

“Not at all. But I figured since we already went to the trouble making it…” 

“Making what…?” 

Senku connected both wires against the bamboo fiber and a little light started to glow. 

“Ahhh! I see!!! That’s Edison’s..!!” 

Yuzuki smiled as she watched Gen catching up to Senku’s thought. 

“Edison’s light bulb! Made from Japanese Bamboo…” 

“Chrome.. Are you afraid of the night?” 

“...Yeah… It just so pitch dark. Why ask now?” 

“In our time… there is no darkness. Light bulbs erased night from the world. With old man Edison’s incandescent light bulb, we claimed all 24 hours of the day for our own.” Senku started to explain 

With science, humanity defeated the ‘night’. It’s been 3,700 years since its light shone on the earth. And although it didn’t last even moe than a second, its light was nothing like the light of fire. Dazzlingly white the light of science.  

The light that got created by the bamboo fiber was so bright that it even reached the villagers and covered the night in light, blinding those who stood close to it. Yuzuki covered her eyes behind her hands lightly and closed them a little to not get blinded by it as everyone else was shocked by the power of it. 

As bright as it shined, it quickly burned out and nothing of the bamboo was left. Senku stayed on top of the house and looked over the whole place. Yuzuki had lied down near the stairs and looked up at the stars, recognising all the different constellations that weren’t so bright and clear when they lived in the city. Yuzuki would sometime take Senku with her when they were younger to go star gazing at a house far away from the city that was under Yuzuki’s name. 

Gen on the other hand was exhausted from shock and sat down under a tree. “Electricity.. In this stone world… For real… Man… Imagine if you could see this now… Tsukasa…” 

“When I started searching for books on science… The first thing I ever read was a Biography on him….” 

“Oh, I remember those times. You never paid attention at class after that and made the electricity bill skyrocket.” Yuzuki released a tired sigh just by thinking abut it. 

“We’ve made it all this way!!” Thinking about everything that Senku had been through, it filled him with determination and confidence. 

Chapter Text

“But hang on… Gen saved everyone from Magma, Didn’t he? Then is he a good guy?” Suika asked everyone confused as she sat in Yuzuki’s lap. 

Senku, Chrome, Kohaku, Yuzuki and Suika had gathered in Chrome’s hut while Gen was waiting outside. They had gathered so Senku could explain everything from the beginning with all the Tsukasa drama and what had happened with Senku before he arrived at the village.

“Kukuku, He’s not a good guy, or a bad guy” 

“He’s superficial opportunist, through and through.” 

“Regardless if Asagiri Gen is good or bad… We have no choice but to recruit him into the Kingdom of Science. In order to have him deliver the fake information of “Tsukasa! Senku’s definitely dead!” That is the only means we have of attaining victory.” 

“You know we will talk about you being dead part later, right?” Senku avoided eye contact when he heard his sister and hopes to avoid nagging from her. 

“Ohhh! Were you listening, Gen?!” 

“It’s not really hard… This hut doesn’t have good sound proofing either way…” Yuzuki thought. 

“You saw it too didn’t you?! That electricity!! That crazy insane light of science!! Winning or losing… whatever you know… or who is gonna win among Tsukasa vs Senku… does any of that even matter? It’s frickin’ interesting!!! Without a doubt… the Kingdom of Science is gonna be crazy!” 

Gen wasn’t moved one bit by Chrome and shrug nonchalant “The passions of a young man sure burn hot~ But unfortunately, mind do not, Chrome. As the world’s most silver-tongued man… the only things I look out for are my own interests.” 

With not further words Gen walked away and back to the generator while Senku stopped Kohaku to engage in a fight with him as she was fuming at his audacity. GEn was quiet as he looked at the generator, suddenly he turned around and was surprised with a fist connecting with his face. Knocking him off his feet. 

“Are you sure, it’s safe for the mentalist to walk on his own at this time…?” Yuzuki sweatdropped, seeing Gen walk away. 

“Why shouldn’t it?” Chrome tilted his head, even Kohaku is clueless on what the white haired girl was indicating. 

“What about Magma. He is surely waiting for an opportunity to strike, doesn’t he think that Gen is the sorcerer not Senku?” 

Before anyone could answer her, they heard a loud sound and ran towards it. 

“What was that sound…?!” 

The moment they stepped towards the sound, they found Gen lying on the ground with a spear in his chest and blood flowing out. 

“A… Are you alright, Gen…?!” 

“He’s gone… Just look at him, he must have died instantly. Who would have done this…” 

“No, wait!” Senku shouted. 

Yuzuki walked past them and pulled out the spear from his chest and opened his chest to look and finds bags filled with red liquid. 

“It’s a bag full of blood…”

“It protected him.” 

“He’s got them tucked away all over his body!” Suika lifted a bags up as she had searched his body for them. 

“These are crazy!!! From the very moment he arrived in the village, he was prepared for the wors. And he went all-out in protecting himself with these…!” 

“Kukuku, not bad at all. A magician to the very core, aren’t you!!” 

“ sigh He may be a magician to the core, but that doesn’t mean he was unscathed… Come on help me bring him back to the hut, so I can treat him.” Yuzuki waved Kohaku over and the two of them with the help of Chrome carried him back and up into the hut. 

Yuzuki started to make temporary covers for his wounds to stop the blood flow with leaves Suika had gathered for her and sat near him, grinding more medical paste. Senku sat next to her and watched what she was preparing and handed her the herbs she needed. Meanwhile, Suika and Kohaku were keeping an eye on Gen wounds and changed the leaves sometimes. 

“Damn it!! We’ll definitely catch whoever did this!!!” 

“Before we go searching for the culprit, we’ve got a much more important problem to deal with.” Kohaku hugged her legs closer to herself “In his current condition, we’ve no idea when he’ll be able to walk again. But if Gen doesn’t return to Tsukasa the he’ll believe Gen was killed by Senku.” 

“I don’t really believe he would have that kind of imagine from Senku. As far as Senku had explained, Tsukasa would probably think about something different that made Gen not return.” 

Yuzuki added as she filled a bowl with the medicine she finished preparing. “But I guess, we could take it as a probability.” 

Later in the night, Yuzuki had fallen asleep in the corner, her had leaning against the wall on her side. Senku walked over with a blanket and covered her with it. He was kneeling in front of her before reaching a hand out carefully and pulling her pin out of her hair. Yuzuki’s hair unruffled itself from their position and fell softly down. Senku brushed them to the side, so that they wouldn’t disturb her while she slept. He place her pin to the side and turned to Gen when he heard whisper from him. 

“Wouldn’t have thought you would be such a brother…” Gen laughed weakly having seen what Senku had done. Senku just wordlessly raised an eyebrow and waited for Gen to continue. 

The next morning Yuzuki woke up and saw that it was early in the morning and that their patient was gone. She stayed calm and walked out with her pin in her hand and walked up to Senku who was standing outside. 

“Did Gen…?” 

“Yeah.” 

Yuzuki nodded and brushed through her hair to unknot it. 

Moment later Chrome came over and climbed up the hut to see after Gen. 

“This is insane!!!! Gen… He’s gone!!” Chrome panicked as he screamed down to the others outside of the hut.  

“Ahhhh…. He’s probably gone back to Tsukasa’s.” 

“That’s Bad!! He probably ent back to tell Tsukasa about you right?! That you’re still alive…!!” 

“In the first place Gen was a man without a millimeter’s worth of interest for science. From the very start, he probably came without any intent of helping us. But from the very moment that I created electricity… Gen decided right the who he would join… But…” 

“A superficial man will have superficial ways… that is always the rule way follow no matter from what time they come from…” Yuzuki continues Senku’s explanation “I guess in a way that’s Gen’s way to show us what he’s really made of.” 

“...Men are really such trouble no matter what era they’re from.” 

Yuzuki just chuckled when she heard Kohaku, but didn’t deny it. 

“Ahhh!” Everyone looked towards the blond “So then the first battle between Tsukasa’s Empire and the Kingdom of Science… that battle for Asagiri Gen… was won by the Kingdom of Science!!” 

“Bound over one bottle of Cola,” 

“Really now?” Yuzuki chuckled.

“The alliance with the world’s most shallow man was formed. Kukuku, guess there’s nothing left to do… but use all the science I’ve got at my command to make it!” 

“The hardest part would to get carbonated water though…” Yuzuki said to her brother, who nodded in agreement. 

_______________

A little later Suika came rolling back to the others after finishing her investigation in the village to find out who had attacked Gen. 

“You know, calling it Gen’s murder case…. He is not really dead you know.” Yuzuki shook her head when she heard what Suika had to say. “But I guess I was correct with my guess.” 

“Yeah, Asagiri gen made those flowers disappear right in front of Magma’s eyes. In all likelihood, from Magma’s point of view, Gen is the “Rumoured outsider sorcerer that Koahaku brought to the village”!” Kohaku concluded.  

“So then Magma messed up…” Chrome couldn’t keep his laughter in “He mistook Gen for Senku and stabbed him instead?!” 

“Kukakakaka!!! That Gen’s plan ended up working out perfectly!!!” 

“You guys are laughing way too hard. Enough that you are making me start to feel pity for him… and I’m the one that hated him the most!” Kohaku’s turned into her signature cate features. 

“If he were dead, It’d be awful, but he is not. He’s alive! All thanks to the power of Gen’s magic!” Chrome said to them from his position on the stairs. “As far as I’m concerned, pity amongst men is an insult! And being able to laugh at each other is proof of being friends!!” 

“Gen?! Gen.. A friend?! Something wrong in your head, Chrome?! We simply have an alliance with him, nothing more, nothing less.” Senku gritted out 

“Men are such a pain in the ass.” 

Yuzuki said nothing and just smiled at them. 

“So then why does this Magma guy want to kill you so badly, Kohaku?” 

“The reason is most likely,... no, without a doubt it is the village games.” 

_____________

“So he is mad because you won against him and blocked his opportunity to marry your sister?” 

“In short, yes.” 

“Kukuku, So that is how yu got disinherited by your dad, the village chief?” 

“No… well… it might have been the final straw…” Kohaku sheepishly looked to the side. 

“She’s done all kinds of stuff for a long as I can remember.” Chrome added deadpanned.

“Of course, they’re going to redo the village games… starting next month.” 

“So that is the reason why… that bastard Magma killed Gen?!” IF someone like that becomes chief, it’s gonna be awful!!” 

“If Magma is able to become Chief… Even if we;re able to create the cure all, he definitely won’t let Ruri take it… That’;; make things really difficult. I guess the dream of getting more citizen for the Kingdom of Science is still a long way away.” 

“Not necessarily! This actually may be a chance! If a man from the Kingdom of Science defeats Magma and wins… They can marry Ruri and become Chief!” 

With little contemplation, Kohaku walked up to the two guards with determination to save her sister from the brute named Magma. 

“Kinro, Ginro. I have something to ask the two of you. What do you think of my sister Ruri?” Kohaku forced out as the two wer shocked and sweated profoundly “Do you want to marry her as your wife?” 

“Errrr~ Well… I… I hadn’t really considered it… But Ruri… I mean, Lady Ruri is really cute…” Ginro started with a heavy blush “Err, I mean, her face… is pretty much identical to yours, Kohaku… But she’s got huge ti… err hughes tides of cuteness that just wash me away…” 

Yuzuki cringed internally with Kohaku who still couldn’t believe that she had asked these brothers about what they thought about her sister. 

“... so all you care about is her face? All you look for in a woman is her appearance? You’re scum, Ginro!” 

“What the hell? I said I dig her big ol’ ti… tides… didn’t I?” 

“My answer is simple. ‘A gate keeper will not ask nor answer.’ Rules are rules.” Kinro crossed his arms “But if I just happen to hear you muttering aloud then that wouldn’t be breaking any rules. I already understand what’s going on. And I know that Senku is not evil. So leave out the usual long explanation and tell e what it is you want!!” 

Both Ishigamis had a grateful look, Yuzuki’s eyes shined with respect and her hear felt warmer at Kinro’s confession about the situation. She turned her head to her brother and saw his expression, she smiled warmly. 

“If you don’t know him very well than you wouldn't even see that his eyes are filled with gratitude. And even if he would never say it himself, he has already let them in as his friends.” 

“I want to save my sister’s life.” Kohaku let her vulnerability show only for a little bit as she told them directly what she really wanted. Kinro and Ginro soften a little and changed immediately, both of them became serious with her statement. Both of them knew that Kohaku would never show them this side of her, when she didn’t really feel like she needed their help seriously. 

“Very well. Then I do not need any further explanation.” 

With that Kinro and Ginro started to train with Kohaku, preparing for the upcoming tournament in a month. 

“Too weak!! Do you really think you can beat Magma like that?!” Kohaku attacked the brothers with all her powers, forcing them to block her without getting a chance to attack her. Both of them fall back and Kohaku backs off to let them take a break. Meanwhile Chrome is sitting in his hut and looked on with a feeling of envy. 

“...To be honest, Chrome…. It was you who I wanted to train. But the only ones that have any possibility of defeating Magma are Kinro and Ginro. I’m sorry.” 

And without remorse Senku added his own evil words. 

“She’s saying sorry to you, since you’re in love with Ruri! Even though ou’re the one in love with her, Kinro or Ginro are gonna be the one to marry her! Sorry bout that, Chrome!!” 

“Do you always need to rub it in…” 

“Don’t be rude now, Senku…” Yuzuki and Kohaku shook their heads as they watched Senku tormenting Chrome. 

But it seemed like that even Senku’s words did not phace Chrome for one bit as he continued to look peacefully at them. 

“IT’s fine. I’ve no problem with that. If I can heal Ruri with Science’s cure-all and if she can be happy…. Then that’s all I want. After all I am a genius scientist!” 

The Ishigami siblings smiled at his statement before Senku started to chuckle again. 

“Kukuku, I thought you were a sorcerer. Did you hae a class change to a scientist?” 

“Yeah, I won’t call myself a sorcerer anymore!” 

“We’ll leave the village games to the battle team, and as the science team, we’ll take on the sulfamide route!” 

“All right! So what will science create next!” 

“In order to create civilisation there is a material just as important as iron…” 

“Glass, right?” 

“Yeah, Nee-san. Any experience in glass blowing.” Senku turned to his sister waiting for an answer. Sadly he could only sigh when he saw her shaking her head. 

“No, sorry. All I learned is how to make a steady ball with it, nothing more.” 

“Well, it was worth a shot.” 

“Whoa, wait. What now? Now that we have electricity, weren’t we gonna make all kinds of medicine?” 

“Yeah, we will.” 

“In order to make our medicine, we need a material that will be able to hold all the chemical experiences we are going to make in them. The things you all had made are a good start, but the level of resistance towards the chemicals is not high enough and they would break the moment they come in contact with it. The chemicals would dissolve the mixture of the ceramic. At least that are known for dissolving things like earth material.” 

Yuzuki explained calmly as Senku lifted one of the ceramic flasks. 

“Kukuku, finally. With glass… We can take off that damn thing that’s always in the way.. So that the mysterious true face of the ace detective Suika…” 

“Wait, Sen-kun…!” 

And without hesitation Senku pulled Suika’s helmet off even as his sister tried to grab him. 

“Might even be worshipped!” 

Chrome and Kohaku screamed at his action while Yuzuki couldn’t help but drop her forehead against Senku’s back in defeat. 

“Hang on, Senku!!! She said she didn’t want anyone to see her face…”

“Go on and look. Her face isn’t all scarred up and isn’t super ugly or anything like that… It’s not like there was even any reason to hide it…” 

Suika was a cute little girl with an adorable short haircut. She blushed a little in embarrassment when the helmet disappeared. Koahku couldn’t help but adore Suika’s appearance. 

“Oooooooh! Suika!!! You’re soooooooo cute!!” 

Even Chrome was surprised when he saw her face but that didn’t stay long. Suika scrunched her face up, wrinkles appeared everywhere as she looked at the four. Kohaku and Chrome were shocked and freaked out. 

“So she needs glasses…” Yuzuki held her chin as she thought about the helmet. “You think it’s the pinhole effect in the helmet?” 

“Most likely” 

No one was paying attention to the white haired duo as they talked, but that changed quickly when Suika started to explain why she  was wearing the helmet in the first place. 

“Suika’s eyes, they have blurry disease. I can only see faint fuzzy images of things, and if I strain to see… Then my face ends up like this, And it’s embarrassing…” 

Yuzuki felt bad and she and Senku walked up to the little girl. Yuzuki placed her hand on top of her hair and rubbed it before helping the little girl to place her helmet back on. 

“But when I wear this Suika cap… Somehow it gets way easier to see!” 

Senku stood there with his arms crossed as he looks down at her and explains why that is. 

“Ahhhh. That’s the pinhole effect. By peering through a hole, light squeezes through it. It can reduce the amount that something is out of focus.”

“Does Suika’s inability to see and glass have anything to do with each other?” Chrome’s curiosity was peaked. 

“Yes, it has something to do with each other.” Yuzuki answered while Senku was reaching his limits with Chrome’s slowness to catch up to their train of thoughts. 

“But it’s not a disease and it’s not a defect or deformity.” She kneels in front of Suika, Senku joins her and places his hands on Suika’s shoulder. 

“In a scientific civilization, not one person is held back by it because not one person would think twice about.” 

Right now the group found themselves somewhere on a mountain collecting crystals. 

“It’s right around here… That I found those clear rocks back when I was a kid!” 

“That little piece of information is priceless.” Senku smirked at the rock that Chrome was holding up. For the rest of the day, until they had gathered enough, they spent at hitting away to collect enough Silica.

“After collecting them, the harder, more physical part would to make them into a fine powder so we can heat them into a thick liquid and form it into anything we like.” Yuzuki sweatdropped, just thinking about all the work that has to go in and all the shouting that is going to happen soon. 

“What are the other ingredients?” Chrome asks while Senku puts a bowl full of Silica into their oven. 

“Ahhh… We’ve already got them all… Now we just gotta work hard here.” 

Calcium carbonate… shells 10%! Roasted seaweed, 20%! All the things we used when we made soap. 

Senku was heaving air into his lungs after a whole night of pumping air into the oven to liquify the glass. Suika was standing next to him and fanning him with a leave. 

Yuzuki was just lying on the floor and closed her eyes for a few minutes, her chest was trying to get as much air back as possible. It may have not been the smartest idea to lie down but she just kept her eyes close until the dizziness disappeared as she calmly breathed deeply. 

“Next, we just hammer in lead…” 

Afterwards they transferred the liquid into a form and acquired a crystal clear glass which is perfect to make lenses for Suika. 

Senku lifted the piece up into the air as the sun caught it and made it sparkle. 

“WOOAAH!” 

“It looks just like ice!! It’s so clear and sparkling!!” 

“It’s almost like a jewel!” 

“What’s that weird looking tool there for?” 

“If we were to try to file down glass by hand, we’d die before we finished.” 

After finding the perfect stone to file down the glass, Kohaku went back to train Kinro and Ginro while the others started on slimming the glass down to start making eye tests with Suika. Senku had done the rough filing but let Yuzuki take over when it came to the finer work, 

They had made a simple but effective eye test for Suika and something simply made out of a stick and leaf for Suika to cover one of her eyes while they held the glass over her eye. 

They made sure that Suika could see  through them and Yuzuki finished them up as Senku cut out holes into the helmet so they could place them inside. 

“Alright!! It fits perfectly into the Suika cap’s eyes!” 

“Wait… so in the end she’s gonna still be wearing that?” 

“As long as she feels comfortable, than that’s for the best right?” 

“I guess…” 

They walked all the way to a sunflower field with Suika and searched for a perfect spot where Suika could test out her new glasses. 

“Suika. Are you able to see what’s in front of your eyes right now?” 

Suika stared at a blurry sunflower. 

“They’re just some regular sunflowers. It’s not like I can’t see them at all or anything…” 

Before Suika could continue, Senku had already placed her cap back on her head and Suika was mesmerized by the view she now had. 

“ Yuzu-nee you are sooo beautiful!” Suika said in amazement before she turned towards the two boys. “Senku!! Chrome!!! You guys look a lot cooler than I expected!” 

“Thank you, Suika.” 

“What exactly did you expect?” 

“Kukuku, Now the Kingdom’s labor force has powered up! With glass utensils and implements, we’ll be able to make all the medicine we want!” 

“Labor force?! Why do you always have to ruin a good conversation with that kind of talk?!” Chrome complained. 

The four of them had decided to have a picknick near the sun flowers before heading back. Yuzuki had gathered a few sunflower head for later and sat next to Suika as she watched the two of them picker with a smile. 

After shutting Chrome up with his bluntness, Senku turned to his sister. 

“Hey, Nee-san. How are your eyes?” 

“Huh? Her eyes, do you mean she also has the blurry disease?” Chrome was shocked at the information.

“Mmmm~ They are fine. I can see without a problem now. I guess it has something to do with being petrified or something. Like some kind of healing ability or that sort.” 

“Yeah, you’re spot on.” Senku nodded “Somehow the petrification regenerates everything that lies under.” 

“You gambled with that with your life didn’t you.” Yuzuki raised a brow. 

“Hey, that it wouldn’t work was slim to none.” 

“You still weren’t hundred percent sure it would actually heal you though.” 

Senku didn’t say anything and turned his gaze away as sweat gathered at his brow. 

Suika and Chrome didn’t dare to join this conversation so they kept quiet and watched.

Chapter Text

Finishing their Picknick with the sunflowers, they collected everything and walked back to continue making more glass material for the experiments. Yuzuki had a basket full of sunflowers while on of her hands was clasped together with Suika’s. Suika swinged their hands back and forth while she skipped all the way back to their hut. 

“Onee-san, what are you going to do with the sunflowers?” 

“Mh, do you see the little seeds here?” Yuzuki pointed at the center of the flower “if you dry them correctly than they make really good snacks.” 

Suika’s eyes sparkle when she heard that,even Chrome was interested in that. 

“Eating sunflower seeds is also beneficial for the body. Break the shell and eat the inside of it and it will have benefits for heart, the immune and the metabolic health.  They also provide healthy fat, fiber and plant based protein. They also have a blood-sugar-lowering effect due to their plant compound chloride ich acid.” 

Senku chuckled when he saw how his sister bombarded those two with her knowledge. Suika and Chrome were trying to digest the new information as they arrived.

“Ah, I understand.” Chrome understood it for the most part. “I think…?”

“I don’t…” Suika kicked the ground as she sulked. 

Yuzuki chuckled and placed her hand on her cap. “Just remember that they are tasty and healthy. Still you shouldn’t eat too much, ok?” 

“Ok!” Suika nodded vigorously while smiling up brightly. 

______________________

In order to make Ruri’s medicine this is where we must begin. Steadily… Honestly working and collecting tools and utensils to create a lab…! 

Without one, we won’t be able to create anything remotely that would be of use for Ruri’s health. 

“Kukuku, Now let us begin our exciting glass-making class!” 

“Yeaaaah! Let’s crank ‘em out!!!!” 

Chrome and Senku started the process of micing all the Silica that they had collected and melted it. While it heated up, it started to bubble and liquify. 

“Whoaa! There’s some white bubble looking thing coming out of it!” 

“It’s the same stuff that’s discharged from when obsidian bubbles and boils.” Senku grins looking at the excited Suika. “We’ll use this here for insulation to create out glass-making furnace.” 

“And than with an iron straw we’ll blow the glass and expand it!” 

Yuzuki was currently not there, she was searching the area for more plants and scouting how the surface might have changed over the time. That’s why, Chrome took over the job to try and blow their first glass bubble into their desired shape. Before Yuzuki had left, she and Senku went over how glass blowing worked in theory. Now Chrome was following Senku’s instructions. But the results were less than desirable for everyone. 

If they wanted to present their creations in a museum, than maybe even those wouldn’t accept these monstrosities. 

All test they did came out as weird blobs that didn’t help them in anyway to somehow master the arts of this specific craft they needed. 

“Kukuku, well, it’s only to be expected at first. When I learned to make earthenware, it took me a few months of straightforward and steady honest work of making them.” 

“A FEW MONTHS?! We don’t have the time to kick back like that!!!” 

“What about Ruri’s condition?!!” 

“Well, we don’t have a glass artisan, so all we can do is trial and error. Nee-san’s knowledge as good as she is, we would still need a master.” 

“Artisan….?” Without a word Chrome ran back to the village. 

Senku and Kohaku didn’t know what he wanted to do and could only look after him. While they waited, Kohaku went back to train the boys while Senku tried another time to maybe get the hang of it. 

Meanwhile Yuzuki also came back with a haul of mushrooms, she had woven a basket that she was now carrying on her back. 

“So how is the glass blowing coming along?” 

Without a word Senku stepped aside and showed her the trials they did. 

“Not good I see…” she sweatdropped as she lifted one, that looked at least a little bit like something that could work, but the thickness of the glass were uneven and the surface was too wonky to be even used and mix anything inside of it. 

The next thing they knew, they saw Chrome walking back with a man tied in a rope walking behind him. 

“What is he doing with the old man….?” 

“I have no idea…” “Hey… knock it off will ya, Chrome?!” 

“Who the hell… is this old man?” Senku would do a lot but even that was a little over the top for him. 

Chrome completely ignored him and turned around to the old man begging. “Please, old man Kaseki! We need your artisanal skills!”  

“Binding people up with straw rope for some hot bondage action is your way of asking people for help?” The Ishigami sibling exchanged a disturbed glance and continued to see were this whole scene was going. “I’m not gonna give one lick of help to a pervert like you!” 

“Damnit, I told you that’s not what’s going on here!” Chrome sweated terribly. 

Chrome was quickly ignored when Suika walked up to Kaseki and returned the thing she had borrowed from him. 

“Old man Kaseki… it totally slipped Suika’s mind and she forgot to return the lacquer she borrowed.” 

“Oh that’s right.” 

Senku and Yuzuki both looked between Kaseki and Kohaku’s shield she was wearing on her back. 

“Wait, isn’t Kohaku’s shield….” 

“Yeah… “ Senku remembered the time when they needed something to coat their cobber wire and asked Kohaku about the lacquer. 

“Was this old man the one that made that? THat finely crafted shield? All without any iron tools or the least bit of dyes…” 

“Yes. It was originally a gift to Kohaku’s father, Kokuyou when he won the last village games. I really put my all into making it… ahhhh, that takes me back.” 

Yuzuki stepped closer and looked at it more in detail, fascinated by his craft.

“We would need incredibly high crafting skills to be on par with the level of our civilisation so I had been thinking about how we needed a masterful artisan. But I never thought it’d be this old hobbling man here.”

“You really shouldn’t say that to a man who may or may nor be our last resource to finish up faster than initially…” Yuzuki sighs as she watched Senku talk.  

“That incredibly suspension bridge there must have been your work as well then?” 

“Yea, that’s right! And you went and ripped out a pank from it on your own!! I’ll never help the likes of you…! Neve..” Before the old craftsman could finish, he caught the sight of the glass that Senku and Chrome had made and couldn’t help but be stunned at what he saw. “Wh.. what is this clear masonry work..?!” 

With that Senku and Chrome saw their opportunity to rope Kaseki in. 

“Why do I have a feeling this is going to be very hurtful to watch…” 

“They look more like bad people than scientist that are making a cure for my sister…” 

Kohaku and Yuzuki, who held Suika’s eyes closed from the view, stood at the edge and watched as the boys continued to taunt the poor old man. 

“Can’t you say something to him?” 

“As if he would listen… For him it’s nothing major that he is doing, so he wouldn’t listen.” 

Both girls could do nothing but sigh as they watched, pitifully and with a handful of second hand embarrassment. 

“They are messing around on purpose, aren’t they?”

“Definitely.” 

“What is going on?” 

“Oh, sorry Suika.” 

Yuzuki uncovered Suika’s eyes and let her watch the show the boys were doing. The longer the three watched the more did Kaseki jump in protest and disbelief that these boys could have no amount of craftsman skills in their fingertips. 

“Kukuku, As a man who’s dedicated and devoted to the craft with the feat of glass-making being dangled like drool before your very eyes. Can you truly sit still quietly there?? Old man Kaseki?” 

Without hesitation, Kaseki broke the ropes he was tight with as if they did nothing at all. They ripped and fell from his body as if they were mere spider webs that had been wrapped around him. 

“Of course not!!! Fine then!!! I can’t resist at all, you got me!!” 

What everyone didn’t expect his for him to rip his shirt too and show everyone the amount of toned muscles he had gathered up all his life as a craftsman. Everyone was shocked and Yuzuki quickly covered Suika’s eyes again and turned her face away out of respect while Koaku covered her eyes. 

Senku and Chrome on the side, had front seat as they got blasted at with a full view of Kaseki’s muscle body. 

“Let me do it!!” Kaseki had a disseminated look on his face as he held the metal tube in hia hand and went to work immediately. 

“Whooooaaaaaa!!!!” 

“Seriously?! He’s ripped!!” 

While Chrome was amazed and stunned, Senku was swaying a little with the breeze and sweating a river after witnessing the scene. No modern person would believe that this old timer would be more ripped at his age than any body builder.  

With practised expertise, craftsman Kaseki formed the first glass in a perfect shape. 

“!!! Crazy!!! Awesome!!! THis is the first time old man Kaseki’s ever seen glass, isn’t it?!”  

“Kukuku… that’s the difference in the level of craft.” 

“I’ve been working as an artisan for 50 years now. So I’m rather skilled.” 

“This is something that exists no matter what the era. Someone who exists quietly, devoting their whole life to their work. A true man of skill.” 

“You got that nostalgic look on your face again, Sen-kun.”

“Shut up…” 

Yuzuki just chuckled as Senku walked away as if their short exchange hadn’t happened and they started building their lab with the help of old man Kaseki. 

Yuzuki had drawn a layout on how the interior should look like after they had finished building the outer lab. Kaseki continued to blow glass and slowly they filled the lab with all the basic essentials that would help them. 

Yuzuki nudged Senku lightly at the side as both of them stared at the finished lab, both of them couldn’t help but thing back at the time when they were younger. Senku walking up to his room and opening his door, seeing all the new science gift. He was over the moon as he saw it and immediately looked and tried everything. What he had not known at that time was that their father Byakuya had sold his car and Yuzuki had worked overtime and more small jobs to buy him everything to start his researches. 

The older Ishigami’s had leaned against his room door and watched him for a while before Yuzuki had stepped in and joined him, listening to all his plans and research he wanted to do with the new gadgets he had. He was so excited and happy, normally Yuzuki would borrow those things from friends or the school, or Senku would somehow built it himself or he would ask his sister to built it for him. Which Yuzuki remembers more as constant nagging her, which bordered begging, but Senku would never admit it. 

“Ohhhh! What’s wrong, Senku? We finally got our lab!! You should be happier!!!” 

“Yeah. Indeed, I am happy. Starting now, the sun rises on the darn of chemistry. Things have finally become wonderful!! Here, where we’re filled with 10 billion times more fun exciting attractions than Tsukasa land. In the Kingdom of Science!!” 

The map of the Kingdom of Science expanded. They now had a science storehouse, which is the stronghold of the Kingdom and is filled with a mountain of treasure. Next to it they have their new built lab where strange, mysterious medicines and drugs were concote. Their power plant, which was a passionate hand power electricity power plant, and the ultimate in eco-friendly energy. An iron-making furnace and a glass-making furnace, as well as a annealing oven, where the glass gets cooled at a slow and steady temperature. Their ramen shop which started everything and a training ground where Kinro and Ginro trained with Kohaku mainly right now.  

Chapter Text

“Did you really have to scare that boy so much…” 

“I don’t see your issue with it, wouldn’t you have done the same?” 

“Probably…” Yuzuki continues to rummage through all the materials they had. “It’s pretty hard to explain it later without him being even more scared.” 

“Exactly” 

Both Ishigami’s are searching for the material to turn Ginro’s spear into a silver spear. After finding it they walked back to the others who finished preparing the pot where they stirred all the ingredients together. 

“Whoa…! So these thin Hair-like things are silver?” 

“Crazy! I totally thought it was the root of some plant or something!!” 

After watching other the boiling pot and everyone sitting around they dipped the spear into the liquid and waited for it to harden. 

“At last!! At long last!” Ginro was crying and snotting all other as he held up his new spear. “A silver speaaaaaar!!! Thank youuuuuuuu Senkuuuuuuu!!”

“Is he always so dramatic?” 

“Yeah…” 

Yuzuki and Kohaku had bonded other the time the others were busy and now Yuzuki gets her girl time and less chaotic time with Kohaku. Kohaku had never thought how grateful she would be to have someone, that was not an idiot boy or a science freak to talk with. Both of the girls just looked on and accepted their fate, that this will be their near future until they don’t have Tsukasa hanging above anymore.

“Kukukuku, I don’t give a damn about your thanks, after all I didn;t make it for you. We need to hurry up and get going already. On our journey to acquire the most difficult of materials.” 

“Hmm?” GInro didn’t register anything Senku was saying as he continued to kiss his new spear head. 

“Ginro, your job is to protect the team.” 

The five of them began their journey to gather the next ingredient for the medicine. Kinro, Kaseki and Suika stayed at the camp. 

“You should have stayed back.” 

“What? And let you all have the fun?” 

“That’s not what I mean!” 

“What do you mean than, Sen-kun?” 

Yuzuki and Senku walked at the back of the group right now as they talked, letting the others lead as they still had a long walk before they reached their destination. 

Senku didn’t say anything and just glared at her side profile. 

“What?” the older Ishigami couldn’t help but chuckle as she turned to her younger brother. 

“You really shouldn’t come with us.” 

“I’m not a child, Sen.”

“I know.”

“I have done this before.”

“I know.” 

“Than why don’t you want me to go?”

“...”
“ sigh Did you promise kyo…?” 

Senku just stuck his pinky into his ear, which was enough for Yuzuki and she just sighed again and ruffled his hair and walked towards Kohaku, who was walking in the front. 

“Don’t worry about it. Nothing is going to happen.” 

_______________

After a while they reached the hot springs. 

“Huh? Isn't’ this the hot springs that I always come to to get hot water?” 

“You said it was maximum danger level, so had braced myself.” 

“The real danger is still ahead.” 

“Ginro. Quit playing around and walk with your spear pointed forward.  THis silver spear is our sensor. THat’s the reason I made it. Look veeeery carefully at the tip of the spear.” Senku grabbed the front of the spear and pointed it to the front, stopping Ginro’s movement as he listened. “If the sparkling silver of this spear should change color and become black… If that happens, then withing just a few seconds you will die.” 

Senku’s expression changed to a dead serious one while he explained the real reason for the spear and Ginro felt a shudder run down his back. 

“So you need to book it in a flash. When that happens, we’ll be running our asses off too!!” 

Without hesitation he went to the back of the group and stayed there for good measure. Right now the group was looking at a small river, to see if they were on the right track. 

“There’s no fish in this river at all.”

“Yeah. That’s just emerald green Chatsubomi moss.”

“So that means we have to go upstream to reach our goal.” Yuzuki added to his finding while he stood next to Kohaku and watched Ginro messing around at the distance. 

“Goal?” 

Everyone turned around and looked at Ginro’s shaking figure as he held out the spear.

“The hell are you doin’ walkin’ in the back, Ginro?! You’re supposed to be our sensor!” Senku went off and screamed at him. 

“B…But you said I was gonna die!!! I’m s-scaaaaaared!!!!” 

“Should I take your place?” Koahku offered “Gimme that silver spear.” 

“No way.” he denied. “I’ll do it.” he gave her a mean stare, nervous sweat covered his body as he passed the warrior. 

This time Ginro walked in front of the others, hands clasping the very end of his spear as he held it as far away from his body as he could. Kohaku and Chrome walked in the middle while Yuzuki walked next to her exhausted brother, who tried his best to keep up with the others climbing the hill. 

Before they knew it, Ginro came to a stop, looking down on a beautiful pond. 

The villagers looked amazed down at their finding. Senku on the other hand, leaned heavily against the nearest stone, trying to catch his breath. 

“We’ve made it. Senku. Yuzuki-san” Chrome stood there amazed, seeing that the material they need for their next ingredient to be found this easy. 

“Yeah… sure enough. We’ve found it. The source of the hardest material acquire.”
“We can be glad that there was one this close.” Yuzuki added, she stood behind her brother’s leaning figure and handed him a skin filled with water, which he accepted gratefully. 

“Even me, who had no idea what we came here to get… Can well enough tell that this is our goal. That is just how… Divinely beautiful this place is. The emerald green spring.”

“This placement is not very ideal.” 

“What do you mean, Yuzuki-san.” 

Yuzuki and Kohaku stood a little away from the others as they gazed around the area. 

“Mmmh, the green spring emits a poison gas which is heavier than air. But because the spring is lowered, its gas can’t leave the enclosement, it’s like a basin. You can say it’s pretty beneficial for us. Although, we would have to climb down and collect it.” 

“Don’t we have just to be fast in collecting it, than nothing would happen right?” 

“No, that wou–!!! Ginro!!” 

“Get back, Ginro!!!” 

Luckily Kohaku was fast enough and she pulled Girno back before the spear turned fully black. The next thing the group witnessed were bird flying other the basin and diving down into the spring and their feathers melt away until nothing was left. 

“UWAAAAAAA!!!! GET AWAY FROM MEEEE!!!!”
“CALM DOWN!!! No one is there!!! There’s no one there, Ginro!!!” 

“They dissolved… the bird’s feathers….”

“Wh-wh-what the hell?! Just what is this spring water?!” 

“Nothing you should play with recklessly.” Yuzuki crossed her arms as she watched the spring with a calculated look. 

During the research of alchemy, they had discovered this forbidden nectar which presently is one of the fundamental cores of all chemical industries. That chemical’s name is…

“Sulfuric acid.”

________________________

Back in the village and at their base, Ginro sat cowered together under the hut with his now black spear in front of him, traumatised by the event. 

“So then without that sulfuric acid… can we still make Ruri’s cure-all?” 

“No, it’s impossible.”
“At least not with the time we have right now.” 

“And on top of that, if we don’t secure a source of sulfuric aid, then we won’t be able to progress with an chemistry from here on in either.” 

“We would be at a complete stand still.”

“THEN THE ONLY WAY WE CAN GET IT IS BY FORCE! IF IT’S TO SAVE MY SISTER, THEN I’LL RISK MY LIFE AS MUCH AS TI TAKES! WITH MY SPEED, I SHOULD BE ABLE TO HANDLE THIS….!” 

Senku stopped her by her shoulder before Kohaku could run off and loose her life. 

“That won’t be possible, Kohaku…” Yuzuki leaned against a tree, gazing down on the floor, thinking what they could build to achieve their goal safely. 

“...Back in the era we’re from… there was a group of people that went out to investigate a similar sulfuric acid area. The man that was taking the lead needed to fix his shoelace so he knelt down to tie it. And he died.” 

“Beneath where he knelt down, the Hydrogen Sulfide had accumulated. This is an actual accident that happened. If mother nature were so inclined, she could wipe out humanity in an instant. She is unpredictable.”

“This is regardless of what kind of super speed you may have, Kohaku. You can’t outrun Mother Nature in everything.”

“THEN IN THAT CASE. WHAT ARE WE SUPPOSED TO DO, SENKU?! I HAVE TO SAVE MY SISTER, RURI!” 

Kohaku started to get desperate as Chrome and Suika tried to swallow this new information. 

“It’s obvious, isn’t it?” 

“Masks, right?” 

“Exactly. WE’RE GONNA MAKE GAS MASKS!” 

With a plan, everyone started to prepare for their trip to the spring again. Chrome, Kaseki, Senku and Yuzuki worked on the gas masks. 

Yuzuki and Senku looked at the first mask they had finished. 

“Kukuku, I wonder just how much this will be able to withstand… it’s not like we can afford to go with trial and error here.” 

“One misstep, one error means game over for us. How good do you think will this bamboo mask hold, Sen?” 

“Hopefully, enough for collecting the first patches and until we can make better ones.”

“Mmmh.” Yuzuki nodded as she worked on the bags that would hold the glass bottles. “You know that I won’t let you go alone, right?” 

“....”

“You don’t really think, you could leave your older sister here alone, while you risk your life.” 

Senku simply looked away and ignored what she was saying. 

“I know I can’t make you stay, so you would have to simply accept that I’m going with you.” 

“...” He grumbled and sat down next to her, picking up the edge of her work and fiddling with it. “He told me–”

“I don’t care what he told you or what you promised him. I won’t let my younger brother risk his life. I could also just tie you up against a tree and collect the sulfuric acid alone.” 

Senku stilled, he knew that that was true. His sister would, she definitely would do that. Both of them knew that he was way to stubborn sometimes. She would probably tie him up against a tree like she said and make Kohaku keep an eye on him while she collects the sulfuric acid. Maybe even go alone without Chrome or Ginro, just to keep them all safe. She is the oldest, next to Kaseki, and she would do anything to keep them alive and safe. 

_________________

Later that night, Senku was with Chrome, talking. As much as Senku accepted that his sister would go with him, he didn’t want to take Chrome with them with the same thought his sister has. It’s unnecessarily to get that boy into danger when it would be enough for both of them to go. 

Meanwhile, Yuzuki was enjoying the night breeze, letting Senku deal with whatever he had wanted to do. She wasn’t really interested in that and she trusted her brother to make the right decisions. Yuzuki was sitting at the edge of a cliff, a little further away from the village and their entrance, her feet dangling over as she gazed over the ocean surface. 

“I wonder how he is doing? Would he be awake already?” Yuzuki sighed and leaned back against her hands and stared at the stars above, tracing the constellations with her gaze. 

“Time is passing by so fast, we are the same age now, huh.” Yuzuki chuckled, her back hitting the ground as she used her jacket she wore as a pillow, intertwining her fingers on top of her stomach. “I wonder how you are doing. Are you still petrified or did you wake up?” 

Yuzuki stared at the night sky for some time, listening to the sound of the night. She closed her eyes briefly. “I wish I could have seen you one last time…” 

“I really miss you, Kyo…” A lone tear slid down meeting the ground. 

______________________

“I miss you, Zuki…” Without his knowing a tear hit the ground as he stared up gazing up at the same stars.

Chapter Text

The next day, everyone worked together bright and early to finish the last few materials for the masks. Quickly they had finished their gas masks, with that the Ishigami siblings and Chrome made their way back to the spring. Senku even cleaned the blacked silver spear back to its original shiny state. Equipped with their gas masks and their sensor they marched their way back to the spring. 

“Ooooooh!! Our poison gas sensor is back!!” 

“If this thing goes back to black, it’ll all come down to our gas masks.” 

“Let’s go then! And get that sulfuric acid..!!” 

Finally after walking for hours through the uneven terrain, they neared the poisonous spring. With the spear held straight ahead, all pairs of eyes were glued to the tip of the spear. Everyone held their breath for a second when the silver spear started to blacken again. 

Senku and Yuzuki froze for a second and regulated their breath to a calm in-and-out. The exchange of oxygen and carbon dioxide in a controlled rhythm is the most crucial thing for their survival right now. 

 Meanwhile, Chrome started to panic, internally mostly. Yuzuki just walked him to the front while Senku skipped after his sister, pass his panicking colleague with a go lucky attitude. The Ishigami siblings have faith in their creation and right now it was either to be able to collect what they came for or die trying. 

“Frickin’ craaaaazy!!” Chrome grabbed his mask hastily to cover his mouth and noise again after screaming. “Seriously?! You two are just rushing on in…?!” 

“If you worry, you’ll just start breathing harder. And if that happens then the gas mask won’t be able to keep up with neutralizing the poison gas.” 

Yuzuki didn’t hear the exchange between them, as she already started to collect the sulfuric acid from the spring and filled their glass bottles with it.

“Kukuku it comes down to a stupidly simple matter. If you get scared, you’ll die. Now if you understand, then let’s get going.” Senku looked over his shoulder and gave Chrome a determined look before continuing his way. 

“Yeah, sure. I get the idea…. But i don’t know if I’ve got the guts, Senku...” Chrome quickly shut up about what he wanted to say the moment he saw Senku’s shaking hands at his side. He understood that even though Senku was showing him such a strong and unbothered front, that even he, Senku Ishigami, was scared about what they were about to do. But without gathering this ingredient, they could say goodbye to any type of invention from the modern era or any era for that. Sulfuric acid was and still is one of the main ingredients that are needed. 

With this new founding, Chrome followed Senku closer to the spring and both of them started to fill the bottles while watching each others back as well as Yuzuki’s, as she was already collecting her fill. 

Chrome and Yuzuki focused on filling all the bottles while Senku made it his job to collect the stones that are surrounding the area.  They were all so focused that their job was pretty fast. Yuzuki had finished her bottles and was walking towards her brother to help him and see how much he still wanted to collect when she started to sprint over. Even Chrome ran other when he saw that acid from a bubbled made contact with Senku’s mainline, damaging it in the process. 

“Senku! The mainline of you gasmask… it’s beginning to melt apart!!” 

“Senku!” 

Senku reacted pulled out a piece of glue strip his back to wrap it around but it wasn’t needed in the end, because Yuzuki was already wrapping it with her own to wrap it. 

“That was a close call.” 

“Yeah, thanks. It’s good then we came all togethe…” 

The Ishigami siblings turned to the sound and saw Chrome falling towards the pit, eyes wide open. They started to run up to him, trying to save him. 

Chrome’s POV 

If I dive into the sulfuric acid spring like this… my gas mask will definitely come off… this is seriously crazy. 

I look over to the edge of the spring and saw Senku and Yuzuki-san running up to me. 

Ohh, and here come Senku and Yuzuki-san trying to catch me. DOn’t try to force yourself… it’s clear you won’t make it in time. Damn it…. Just from that one momentary slip… anyways.. I leave the rest in your hands… 

Including…

Ruri…

3rd POV

Miraculously, Ginro appeared and thrusted his spear forward, above Chrome’s figure. Out of shock, Chrome grabbed on it, legs around the wood and hands ear the top of it. Ginro skeed to a stop at the edge of the spring, holding Chrome just above the spring. 

“Ginro!!” 

“So… Heavy…!!!” The hero like move was short lived, he wasn’t someone who could hold another persons weight in this kind of position for long. 

“Lower you breathing, Ginro!!! If you breath that heavy, the gas mask won’t hold up!”

Senku and Yuzuki came running from behind. Yuzuki was the first one to help him with the spear, leaning her body backwards, relieving him from some weight. 

“It won’t hold up?! So the I’m gonna die rom poison gas?!” 

“You won’t!!”  Yuzuki tried to reassure him as she tried to hold the spear above the spring with him, her arms straining against the weight. 

“I’m gonna die now?!” 

“A large amount of activated charcoal and potassium carbonate will absolutely crush out any poison gas! As long as you’re able to control your breathing!!! You’re winning against fear! That’s the whole reason that you came back here on your own, isn’t it?!” Senku questions him. 

“Stop talking and come here, Senku!!” 

“Yeah, Ginro!! THink with here and here! No matter how powerful nature is it had no mind to think with or heart to feel with. And that… that is where we can beat it!” 

Before Senku could move closer to help his sister and Ginro out, Ginro had found his determination again and lifted the spear up with all his might. In the progress, Yuzuki lost her balance and let go of the spear. Senku caught her before she could fall and her back and hurt herself. Meanwhile, Ginro was able to lift his spear back up, with Chrome as additional weight and catapult him into the air and back to safety. 

_________________________

Finished filling all the bottles and placing them in their carry-ons they made they way back to the village without further problems or wounds. Apart from Senku, of course, who probably died mentally multiple time already from just carrying one bottle of their liquid material, desperately gasping for air. 

“I think, we really need to work on you physical health again, Senku…” Yuzuki was walking next to her brother with her own bottles. She isn’t carrying as many as Chrome or Ginro but she was still carrying two bottles more than he was. The weight was still straining her muscles and she may not be walking as unbothered than the village boy but at least her figure wasn’t bend back at a 45 degree angle to the floor like her brother. She could have probably carried more, but Chrome and Ginro took most of the load, not wanting her to carry to much as she wasn’t as physical fit as they were. 

A little earlier

“How are we going to bring these back?” 

“We have a few bags that Kaseki made.” 

Yuzuki was kneeling down on the floor and placing the bottles into the bags carefully. “Who is taking what?” 

“Don’t worry, Yuzuki-san. Now that we have Ginro here, he and I can take the heavier ones.” Chrome stated as he lift the strap of the bag across his body and lifted it up with only minimal struggle, Ginro on the over hand stood at the front already with his own. 

“Man, this is heavy.” 

“Yeah.” 

Ginro only complained a little about the weight but over than that he said nothing about it. Yuzuki and Senku exchanged a dumbfounded look but shrugged. Senku tried to lift up the medium basket, but struggled heavily. 

“Grrrr…” 

All three sweatdropped. 

“Ok, how about I take this one…” Yuzuki reached out and handed Senku the small basket for him to carry. Inside there was one glass bottle. The bottles weren’t small, inside were probably around 2 litres of sulfuric acid. Yuzuki also knew that her brother isn’t good at lifting things or stamina. With that she picked up the medium basket with a little struggle but in the end, compared to her brother she was able to lift it. 

Taking a few steps forward, Yuzuki was stopped by Chrome and Ginro. Both of them took one bottle and placed it in theirs. Now with Yuzuki left with 2 bottles, she stared at them questionable. 

“Don’t worry, it’s not too heavy for us.”

“Yeah, this is nothing, Kohaku makes me carry heavier stuff than this.”
 

WIthout further words, both boys marched off. 

__________________

Present time 

“We’ve acquired the most difficult material… Sulfuric acid!!” 

Suika came bounding over in joy seeing that the group had made it back safely. 

“Ooooo! Thn does that mean… finally.. We’ll be able to make the cure-all for my sister Ruri?!” 

“Kinda jumping the gun, aren’tcha? You saw that crazy road map to making the cure-all before we started, right?” 

“Ngrk.. you mean.. That insanely long thing…?” 

“Kukuku, that's not true at all. In fact, we’ve just about collected everything we need to make it already!” Senku grinned at them with a look over his shoulder while Yuzuki walked over to Kaseki handing him the first blue print for their next step. 

“Now that we’ve collected the materials. All we have to do is trudge through the dark blocks of the road map ahead…. And illuminate them one by one on our way to the goal!” Senku grabs all the glass flask in their laboratory. “And we’ll knock them all out at once, today! Here comes our full-force surge fo chemical cooking!! Now this excites me…!!!” 

“I think we are missing one crucial ingredient though…. But I guess I will let him find that out himself…” Yuzuki just chuckled at her brothers enthusiasm and let him work.

While they worked on cooking up the ingredients, Yuzuki made sure that they wouldn't need her help with anything before she walked away towards the cliff she sat at a few days ago. 

Yuzuki’s POV

“It’s so quiet here… sigh. ” Yuzuki sat down, leaning against a tree and looked over out towards the sea. She sat crossed legged with her hands in her lap. 

“What a day…” Yuzuki leaned her head back against the tree, looking up to the leafs and enjoying how the sunrays filter through the leafs. Closing her eyes, she relaxed her body. 

Her hands, that are resting on her lap, started to shake, her breath coming out a little uneven. The whole event from earlier at the Sulfuric acid spring finally came crashing down. When they were there, she didn’t let the others notice how scared she was. Not scared for her life, but scared that something would happen to them, especially to her brother. Her brother is her one and only, since now Byakuya wasn’t here, or at least she theorised that he wasn’t with them anymore. And since she wouldn’t be able to see Ukyo for some time. 

Tear drops escaped her closed lids, she remembered the fear she had when she saw how Senku’s mainline melted , how Chrome nearly fell into his death, if Ginro didn’t come. All the promises she made to herself. 

______________________

Childhood  

“Onee-san!!” 

Yuzuki entered through their house door and met with an energetic 3 year old. 

“Ototo!”  A 10 year old Yuzuki lifted her younger brother up and carried him further into the house, kicking her shoes off at the entrance.  “How was your day, Sen?” 

“...good. I read this book about stars!!” 

With a little hesitation Senku answered his sister. Yuzuki kept quiet for a bit but smiled at him, nodding her head. “Ooooh. Really, what did you find out?” Yuzuki placed him on a chair at their kitchen table as she walked to the fridge. 

Yuzuki frowned as she walked through the apartment, but she didn’t find a trace of their parents. 

“Seems like they left early…” Opening the fridge, Yuzuki found nothing but a note and some ingredients in the fridge. 

‘Make whatever you want. Money is in the drawer like always. - Mother and Father’ 

Yuzuki sighed softly before taking out meat and vegetables, a few eggs. Senku was still rambling about the resemblances from the stars and planets, sometimes mispronouncing words which made her chuckle softly as she started making their lunch. 

Soon Senku switched from talking about his book to asking questions one after another. Yuzuki answered him with ease, trying to quench the thrist for knowledge from a 3 year old Senku. 

After placing their meal on the table, Yuzuki sat next to Senku and watch him eat before digging in herself. 

Yuzuki smiled softly, a joyous and sad smile at the same time. It wasn’t a new scenario for them. Their parent’s always left early, leaving their children alone in the house for most of the time. Yuzuki always woke Senku up early to feed him, after their mother had went back to work, before she went to school and made lunch and dinner when she came back from school. 

Yuzuki cherished these moments between them, happy that her brother still found joy in the books that laid around the house and the Q&A sessions he did with his sister. She’s glad that he isn’t too bothered with the lack of presence their parents have in their life. 

“I’ll stay and keep you safe, Sen. Always.” 

___________________________

Present 

Yuzuki found herself a stream and threw water on her face to freshen up. She had calmed down at some point and now the sun was slowly setting. 

“I have to go back.”