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Combat Engineer Osamu

Chapter 2

Notes:

(See the end of the chapter for notes.)

Chapter Text

Mikumo can't help the wide smile that stretches over his face as he creates a Trion cube in his hand, splitting it up into a volley of bullets and shooting them at the dummy on the other end of the testing field. 

He has been given more and more triggers to test by his colleagues over the last weeks, and he is enjoying it greatly. 

They have even allowed him to borrow one of the C Rank Triggers without any attack Triggers and take them home! 

It is probably not too healthy that he no longer sleeps during the weekend and spends them fully in a Trion body, but the extra hours he gets from it make it more than worth it. 

It turns out that if the trigger main body doesn't have any attack triggers implemented, they don't use nearly as much Trion to stay active. No one just spent enough time in an unfinished trigger body that it was noticeable, at least no one with low Trion like Osamu. 

Ilia has said they will have to look further into that, since it implies they have some unnecessary energy loss in the interface between the Trigger body and attack Triggers. 

Osamu releases another shot and watches as the bullets curve around in the air, before colliding with their target from all sides, shattering it into pieces. 

Hound is not something Mikumo can use repeatedly, but for testing like this, his Trion is more than enough. 

He of course knew that his Trion was below average, but seeing it like this and comparing it to even the average B Rank agents, and even more so to the A Rank's, is kind of depressing. 

Speaking of A Ranks, he finally got to test an A Rank Trigger last week. Only for a handful of days since it was finished Friday, but now he understands why they are worth the time invested in building them. 

It's really like comparing a sports car with a regular one, just so much more refined on every level, and a power output so far above the normal ones. 

“End testing sequence.” An automated voice announces, and Mikumo deactivates his Trigger, another B Rank this time, as Taru walks in. 

The man has another small bandage on his arm, just like the day Mikumo met him first. Being one of the people to often run tests on the Triggers stolen by the Away Mission, he ends up in explosive situations more often than the rest. 

But he refuses to use any more protective gear, saying that it makes the analysis of the foreign devices even harder than it already is. 

“Did it work out fine? And problems with the Hound?” He asks curiously. 

“I think there was a minimal delay before they activated. Maybe some minor difficulties with the processor?” Mikumo offers. That is usually the reason for that. 

Taru gives him a nod. “I will look into it. Thanks.” The man says as he takes back the trigger core and Mikumo changes back into the Trion body he was using before. 

This one is designed for Yuba squad, so he is wearing their uniform right now. 

He honestly always feels a bit awkward to wear the uniforms of teams he isn't part of, but the B Rank Triggers just feel so much more comfortable compared to the C Rank ones that he uses them anyway. 

It's not like anybody except the R&D members sees him anyway. 

By now he has circled through quite a lot of triggers, and he can figure out pretty fast if they still need to be worked on. 

And through all the testing he has done he is actually getting better at using them too, even if he is unsure how much it would help him out in an actual fight. 

At least it had taught him that he shouldn't attempt to spam Hound in an actual fight with his small resources, let alone Meteor. He would run out of energy far too fast. 

‘Sticking to Asteroid for actual combat would probably be best.’ Because he is a bit too clumsy for close combat weapons right now. 

He and Taru walk out of the testing room together, saying goodbye for now, but Mikumo is sure his coworker will be back in less than an hour to make sure the repairs he made do their jobs. 

Flexing his shoulder a bit, Mikumo returns to the small office he has been given, returning to his table filled with trays of delicate tools. 

They have given him some very simple triggers to build. Mostly the bodies for C Rank Triggers and shield Weapon Triggers. 

And he has gotten pretty good at them, slowly but surely approaching the speed at which his colleagues build those Triggers. 

Still, he has become very thankful for the existence of protective goggles over the last few days. Sometimes he thinks his hair still smells slightly smoldered. 

The work is a bit monotonous, but Mikumo is still figuring out small tips and tricks with every trigger he builds, so it actually feels surprisingly satisfying. 

And his coworkers seem to be happy about his assistance, too, giving them just that amount of extra time that they were hoping for. 

Raizo was especially happy that he managed to complete the modifications on the Trigger for Kazama in time for the next Away Mission. 

Oh, and that is another thing that has the department in high energy. The next away mission is taking place right now, and potentially will bring back more research material.

The Away Mission is on the smaller side this time since the planetary nation they are targeting is too far away for anything more, so it's rather stealth based this time around. 

Still, with it being led by Kazama, the superiors have high hopes, like always. 

And Mikumo can't help but get pulled along by the enthusiasm. Who knows what kind of cool triggers they might be able to build with the new data they get? He can't wait to analyze it. 

Still, for now, he returns to the triggers he is working on. The C Rank body he is working on will take another day, but after that, Taru has promised him to try out how to construct an Asteroid Trigger for himself. 

He can't wait. 

 

_____________

 

“Mikumo, can you go up to the squad room of Tachikawa? Izumi seems to have experimented around with his Trigger and blew himself up, so we need to make sure there aren't any hiccups with it.”

“An A Rank blew himself up? That's unusual. What was he trying to do?” 

“Oh, he is experimenting around with his bullets, but I don't know more. You get that stuff out of him even if he is embarrassed about it.” 

“Roger. I will do my best.” Mikumo says with a nervous smile. He has heard that many of the higher-ranked agents have quite unique characters, so he can't help but be a bit on edge. 

He takes all the tools that he might need, and with his laptop under his arm, he rides up the elevator towards the upper levels. 

The A Rank squads each have their own rooms in the upper area of the headquarters, close to the central offices of the department heads. 

The door is pretty easy to find. Mikumo is by now pretty used to the overly confusing layout of the Border base, even if he now knows that it's specifically built to be misleading to keep out intruders. 

With one last deep breath, he knocks on the door. 

Instead of the ‘come in’ or something of the like, he hears a small crash from the other side of the door, and some voices too muffled to understand. 

He listens to the sound for some seconds before the door opens to reveal a blonde boy, maybe some years older than Mikumo. 

Well, judging someone by their physical appearance is a bit unreliable with how being in a Trion body slows down aging, but thankfully Mikumo recognizes Izumi, the shooter looking at the other boy in slight confusion. 

The brunette goes into a small bow. “I'm here for the maintenance of your trigger. I was informed that there was some kind of incident during training.” 

Izumi's confused face turns to a smile, opening the door wider. “Oh, you are one of the engineers! I didn't know they had anybody like you.” He says curiously, practically dragging Mikumo inside. 

“Yes, I’m a new member. Should I take a look at the trigger right away?” 

“Oh, yeah, here it is,” Izumi says, handing him the tool. 

Mikumo takes the Trigger and observes it with a curious expression. A Rank ones always feel a bit different, seeming to hold a weight the others don't.

Carefully, he opens up the outer casing, taking a better look at the interior. There aren't any obvious signs of damage or smoldering for now, which is a good sign. The A Rank ones would take a while to rebuild. 

Under the magnifying glass, the different structures on the motherboard don't seem damaged either. Even if the trigger is showing signs of regular use, it's kept in good condition. 

“Does it look okay?” Izumi asks nervously over Mikumo's shoulder, watching him work impatiently. “Please tell me I can use it again soon.”

“I haven't found any problems for now, but I can't say for sure yet. I have to run some more tests.”

The blonde continues to look over Mikumo's shoulder, letting out some curious sounds now and then as the brunette goes over the delicate structures of the trigger. 

“Let him work, Izumi,” comes another voice as another pair of steps comes into the room, and Mikumo looks up from his work, immediately finding himself tensing up. 

He stands up and goes into a deep bow, nervously avoiding looking at the older man's face. “Hello Tachikawa-san. It's a pleasure to meet you. I’m sorry for intruding.”

The top attacker just waves him off. “Ah, don't worry. Relax.” He says, walking over to the young mechanic. “Sorry for making you work extra. I didn't think Izumi would mess up like that.”

“It's not a problem. But can you give me a rundown of how the incident happened?” Mikumo asks, looking at the two A Ranks. 

Izumi looks a bit embarrassed. “I was experimenting around with different bullets. Before bullets materialize, they are in a pretty malleable state, so I wanted to try to fuse some Hounds with the explosive power of Meteor.”

He intensely moves his arms as if to bring the point across. “And, you know, the bullets just feel like you can just cram them together, so I tried it out.”

The blonde lets out a small laugh. “I guess I was wrong with that.”

Mikumo looks down at the trigger in concentration, letting the information settle in. “No, I think the idea is a sound concept. Maybe you just did some steps wrong along the way. Let's go down to the training area. I need to make sure your trigger works fine anyway.” Since the operator does not seem to be here, they will have to take one of the public rooms, but it shouldn’t pose a problem.

Izumi seems to be delighted to have someone confirm his suspicion, and he just enthusiastically talks about his idea as the three make it down to the lower levels. 

Mikumo tries to absorb all the insights the shooter gives, making some notes as they talk and throwing in some comments and questions now and then. 

Tachikawa just silently follows after them in a way that makes Mikumo a bit nervous, but the young boy is too distracted by Izumi's ideas to pay attention to his own emotions that much. 

They take one of the empty training rooms when they arrive, and Mikumo doesn't hesitate to activate Izumi's trigger when they are inside, donning him in the black and red robes of Tachikawa squad. 

Like always, an A Rank body makes him feel so much more powerful than normal, but he does his best to focus on his job. 

“The body overall seems to be fully functional, so no problems there.” He says, mostly talking to himself, before turning towards the training dummies. 

He first releases a Meteor at the target, and even if it is draining like always it seems to be working fine. Next he shoots a Hound, watching intensely how the bullets fly in the air to make sure the tracking is working perfectly. 

“Ah, there seems to be some problems with the Hound trigger. Nothing major, but I think one or two of the energy transformers were overloaded and fried. They still function, but if you were to leave it like that, each Hound would use a bit more energy than normal. I will take this back down and replace it with a new Hound trigger. It should only take a few minutes,” He says, turning back around only to find the A Ranks staring at him curiously. 

Tachikawa looks at him for a moment, rubbing his chin, before he starts talking. “The engineers we had till now never tested out triggers like that. They only took them down to the lab. Why are you doing it differently now?” 

“Ah, because the others don't have enough Trion to activate them. My Trion isn't high enough to be considered for a fighter position, but it's still enough for this. So I have been using a lot of different Triggers and memorized how they are supposed to feel. I can usually tell if something is wrong as soon as I activate them.”

“Hm, that sounds pretty useful. Good to have you around.” Tachikawa praises, and the only reason Mikumo doesn't blush is because he is still in Izumi's Trion body. 

“Well, it's useful, I guess, but not compared to what a fighter can do. I'm just trying to do my best with what I have.” He says as he deactivates the trigger, turning to Izumi. 

“So, before I fix this up, do you want to do another test? It really wouldn't make sense to repair this only for it to blow up again.” 

“Yeah, that would be pretty stupid,” Izumi says with a laugh. 

“Okay, just let me link this up real quick,” Mikumo says, holding the trigger to the receiver on his laptop before handing it back to Izumi.

The blonde activates it instantly, radiating pure Trion in a way that Mikumo couldn't even imagine himself doing. 

“Just try out what you were doing before.” Mikumo ensures him.” I will watch where things go wrong.”

Izumi gives him a smile. “Thanks, man! Let's try this out then!” he says, forming a large cube of Trion in each hand, pressing both together while they are still manifesting. 

The process looks simple on the surface, but Mikumo can see the level of skill that goes into the task, carefully keeping the wavelength of both Trion signatures level while still mixing them into each other. 

After some seconds the brunette detects a small shift in the structure, and then the cubes combine into one larger one, Izumi holding out his hands to release the composite bullet. 

But the moment he does, the bullets instantly destabilize, bursting into an explosion. 

Connected to his trigger as Mikumo is, he immediately diverts some power towards the A Rank's shield, creating a small panel just in time as the bullet explodes, thankfully protecting the blonde from most of the blast, but still throwing him some meters back, sliding over the ground and leaving behind a large cloud of dust and smoke. 

“Man, and I feel like I was so close! Thanks for the protection there. Maybe this might not work after all.”

“No, it would work. Does work, actually. The bullets fully fused. You just made a small mistake.” Mikumo turns the laptop towards Izumi. “The two bullets you shot were not programmed to fly at the same speed, so they ripped themselves apart as soon as they started moving.” 

Izumi lets out a loud groan. “How did I miss that? But yeah, makes complete sense. Let's try this again!” he says as two more cubes appear in his palms. 

The bullets fuse just as perfectly as last time, but this time, when they shoot through the air they curve just like they are supposed to, all homing in on the target and bursting into a devastating explosion, leaving behind a crater in the ground. 

“I did it!” Izumi shouts happily, jumping up and down in place. 

“I'm glad I could help. I hope this will be of help during your future fight. “

“Hm, I'm not so sure how much, sadly. The charge-up time to mold the bullets is a lot. That could be a big problem. I don't know yet if I can reduce it enough for it to be usable in actual combat. Though I guess from a safe distance they would always be an option.”

Mikumo takes another look at the data in front of him. “I mean, the general process of the molding seems to be relatively static, so I might be able to write an algorithm to take away some parts of the work.” It should be possible to program that much into the trigger core. 

“You would do that? That's amazing!” Izumi says, catching Mikumo in a hug, and this time, he doesn't have a Trion body active to hide his blush. 

“I can't make any promises if it will work, but I will try my best if you wish to.” 

“That would be amazing. I just know this has so much potential!” Izumi says, and Mikumo can't help but agree. 

After a quick goodbye, the boy excuses himself with Izumi's trigger to repair the Hound Trigger, still a bit nervous about how silent Tachikawa has been for a while now. He hopes he didn't offend the man somehow, but maybe it's just A Ranks being weird. 

 

____________

 

Mikumo is admittedly more than a bit nervous as he walks down the hallway towards Kinuta's office, the report he is supposed to deliver under his arm. 

He has, of course, seen the small man in the hallways before, but never directly interacted with him even if he is his boss. 

And the generally harsh way the man acted towards the combat members when Osamu was watching does not help the boy's nerves. 

Kinuta has been quite busy over the last months since Mikumo started working here, implementing a complete overhaul of the defense systems of the base into its Trion matrix. A new employee really wasn't his priority. 

Mikumo hesitantly knocks on the door, and from behind it, he hears the man's muffled voice telling him to come inside. 

“I'm sorry for the interruption. Here are the reports for this week's progress.” He announces as he steps inside the office. 

“Good work. Anything else to report?” Kinuta asks from where he is buried behind mountains of documents. It seems the busy streak is not over yet until he finishes the backlog. 

“Nothing out of the ordinary. We have worked ahead far enough that we can invest enough time once the Away Mission returns.” 

“That's good to hear.” The man says, a small smile on his face as he looks up towards the boy in front of his desk. “Ah, Mikumo, I don't think we have met yet. It's good to have you here.”

Mikumo goes into a small bow, a blush dusting his face. He didn't expect such a positive reaction. “The pleasure is all mine.” He says politely. 

“Ilia has been praising your capabilities and dedication, and from the reports I see of your work alone I can see it's not unfounded. But don't overwork yourself, okay? You are still young, don't forget that.” Kinua says, and even if the voice he says it in is gruff, the message below it reaches Mikumo easily. 

“Thank you.” The boy simply says, not really sure how else to respond. Maybe Kinuta is a much better person than he thought. 

“I am the one who has to thank you for starting to work here. We have been understaffed since Border's creation. It will be a pleasure to work with you, once I'm through this mess.” He says as he points to the paperwork stacked up on his desk. “Now, shoo. I'm sure you have better things to do than listen to an old man talk.” 

Mikumo takes that chance and leaves the room with one last goodbye, because he, in fact, has something he really wants to do today. 

He only finishes one last document for today before he rushes out of the building, making his way through the tunnels under the forbidden zone and into town, till he eventually ends up in front of a familiar house. 

With a small smile, he rings the bell. “Chika, it's me. I'm sorry for being a bit late.” 

“Osamu! Don't worry about it. I know things can get busy at times.” She says as she opens the door for him, ushering him inside. 

They, of course, see each other at school every day and usually eat lunch together, but hanging out like this is just different compared to that. 

“So, how was work?” 

Mikumo knows she was trying to hide it, but when he first started working for Border, she wasn't exactly happy about it. She knows very well that it was in an attempt to protect her. She knows him far too well for him to be able to hide something like that. 

The fact that he didn't end up in a combat unit helped calm her nerves a bit, but not fully. 

“It's still interesting. I should finally be able to finish my first Asteroid trigger soon.”

She nods along with him, happy for him even if she doesn't really know what he is talking about. 

After Chika saw how much Osamu was working himself into the ground during his first weeks in Border, she insisted that they have a day at least once a week where they just relax together. 

Mikumo has since gotten himself under control a bit, but the meetups have stuck. 

“So, how did you do on your last tests in school? Anything I can try to help you with?” He asks, getting a laugh from Chika. 

“I should be asking you that, you know? Your mom complained to me about your last test in literature.” 

Mikumo rubs the back of his neck in embarrassment. Yeah, that wasn't the best of his work, but it's not something he really uses in Border, unlike math and physics, so he is honestly a bit out of practice. 

And with all his work in Border, school simply isn't a priority like it used to be. And he doesn't regret that decision, even if some of his teachers are visibly worried about his dropping grades. 

‘Maybe they would calm down a bit if I told them that I started to work for Border?’ But he would mostly do that so they aren't as bothersome, and he isn't sure that's worth the attention being part of Border might bring. ‘Though it might not be as bad since I'm not a fighter.’

“I still get passing grades, so it's okay. Kinuta-san already assured me that I will be taken over by Border no matter if I even finish school.” Which is a bonus Mikumo didn't consider when he started working there. 

He turns towards the hallway that leads to the kitchen. “We wanted to try out that new recipe today, right? Let's start with it now so we don't have to hurry.” He says, because he honestly doesn't really want to talk about school right now. 

Being a good student was kind of like one of his identifying traits for a while, and now that has quickly fallen to the wayside. 

But he doesn't regret it for a bit, even if he mentally still has to get used to that. He feels more useful and just in the right place than ever before. 

‘But it would still be good if I could make a combat team for the development department.’

A thought comes to his head, and he turns to Chika with a questioning look. “Do you happen to know anybody who is interested in joining Border?” he asks her. “Even someone who has already failed the entrance test.”

She seems to think for a moment, but then shakes her head. “There’s a  boy in my class who is constantly talking about joining Border, but if someone tells him to just try to join, he says he is too nervous to.”

Osamu has such a classmate too, but even if that boy was interested in joining Border, Mikumo doesn't think he would fit in the development department. Too much studying and sitting still. 

He lets out a sigh. “I guess I just have to ask around a bit.” 

“Why do you want to hire people in the first place? Aren't there more than enough applications?” Chika asks curiously as she takes out the ingredients from the shelf, placing them on the kitchen counter. 

“There are enough applications for the combat side, but nearly no one is interested in development. I don't think many know they can even apply to it, honestly.”

He dumps the ingredients into the bowl and starts mixing them together. “I guess I will just have to ask around. Maybe someone at school has an idea.” 

‘Maybe I should ask Kinuta for some support on the matter. He would probably appreciate some additional help.’

Time passes fast as always when Mikumo meets up with Chika, and before he realizes, the sun begins to dip below the horizon. 

“Promise to not overdo it again.” Chika reminds him when they say their goodbyes. Osamu agrees like he does every time even if he isn't sure he can keep the promise. 

 

_____________

 

“Ready for the tests?” Izumi asks happily as he spots Mikumo hurrying out of the base with his laptop under his arm, the boy already in a Trion body he borrowed from the department, this time with a more official permission. 

The body is just a standard B Rank one that doesn't have its uniform or Triggers fully set, but it will do the job more than enough. 

To test out the new composite bullets Izumi created, they have been sent out for an actual test run against actual neighbors. Despite his non-combat position Mikumo has been permitted to take part in the patrol with Tachikawa squad to observe them first hand again. 

His small additional programs to Izumi’s trigger to speed up the bullet fusing process a bit will be tested too, even if that particular area has not progressed to a high degree yet. At least in Mikumo’s opinion. Izumi seems to be very happy with them.

“Yes, I have everything ready.” Mikumo says with a smile. He has been enjoying the time he spent experimenting around with Izumi a lot. 

With a small click, Mikumo feels himself get added to Tachikawa squad’s come link, Kunichika's familiar voice echoing in his head. “I will tell you guys when I find anything.” 

Mikumo met her when he was delivering Izumi's newly repaired Trigger, and he found that they got along very well. She is a very welcome point of calm in the chaos that the other members usually bring.

“Well, let's hope we actually encounter something,” Tachikawa says, giving the younger boys a small grin. 

A worry that turns out to be justified, as even after hours, they have not encountered a single Trion soldier. 

Still, the time is well spent, as Mikumo and Izumi continue to exchange all kinds of ideas. 

“From a theoretical point, it should be possible to combine more than two bullets, even if balancing all energies out would become exponentially harder to do. “

“Yeah, but one person can only have two active bullets with how Border’s current triggers are constructed, so two people would have to do it together.”

Mikumo lets out a small hum. “And for two people to keep their Trion wavelengths so stable and similar…”

Izumi releases a sigh. “Yeah, that sounds close to impossible, even outside a combat situation. But just imagine the power a triple Meteor could hold!”

The engineer nods in agreement. “The power that could potentially hold might make it worth looking into that direction, even with how difficult it is. But if you would mess up during the bullet compositing and it explodes directly beside you, you would instantly be out.”

Izumi lets his shoulder drop a bit. “Still, I would love to try it out. Do you think you can do anything, Mikumo? Any ideas?” He asks, dramatically letting himself drop against the brunette's shoulder. 

“Well, it would probably be better if we could avoid another person for a triple composite, so we should use something like one of the Trion turrets we usually use for traps. But that would make it very obvious, predictable, and wouldn't allow for much customization or adaptability. “

Kunichika links herself in over the coms. “I think that would still be worth it, even if it's predictable. A large explosion would be useful in everything, starting with breaking a strong defense to altering the terrain. It might not reach its full potential in Rank Wars, but in case of another invasion, it could be invaluable.”

Mikumo nods in agreement. “I will look into it a bit more. I'm sure I can get some of the turret construction plans from Kinua.” 

Izumi’s face shifts in discomfort. “I still do not understand how you get along with that man so well. He glared at me just for breathing! “

“He is a really kind man if you get to know him! He just worries a lot and isn't the best at showing it.” Mikumo says. “And I'm pretty sure he glares at you for blowing up the wall in the training room two weeks ago.” 

“That was one time!” Izumi insists, even if it absolutely wasn't. Especially not since he started experimenting with composite bullets. They pack quite a punch. 

Mikumo hears a small beeping sound in his ear, but over his com and not his physical one. 

“I am picking up a gate in the area. Sending you the location.” Kunichika says in a relaxed voice that Mikumo isn't even close to being, his heart (metaphorically speaking, because Trion bodies don't have those) hammering in his chest. 

In his field of vision, he sees a small map of the area pop up, and the group doesn't waste a second to hurry to its location, Osamu lagging behind the other two a bit. 

“It seems this is a bigger attack, so don't waste too much time,” Kunichika instructs. 

But even from this distance, Mikumo can see the Trion soldier clearly, a Marmod, but… “Are its claws supposed to look like that? “

“Hm, you are right. The claws look a bit different. A slight modification?” Tachikawa asks aloud towards the rest of the group. 

Kunichika takes a moment to answer, probably scanning the Trion soldier. “Yeah, just the claws, but definitely modified. That body part is completely different in structure, even if they are made to look similar. Good catch, Mikumo.”

“Can you tell us what they do?” Izumi asks as he watches several of the creatures spill out of the portal, his eager and battle-ready grin never leaving his face. 

“Sorry, we don't have anything comparable in our system. Just be careful for now. Oh, but not too careful. They are already moving towards the city, so hurry up a bit. I already informed the other squads.” 

“Okay. Let's get to work.” Tachikawa says with a grin, dashing ahead with his head turned towards Izumi and Mikumo. “I will slow them down from the front so they don't reach the civilians. You two focus on thinning them out.” 

“Roger that.” The blonde responds, Mikumo only getting out a nervous nod. This is not how he expected this test to go. At least the rest of the group doesn't seem nervous like him. 

Izumi is not waiting a moment longer as he charges up a shower of Asteroids, raining them down on the swarm of Trion soldiers, but the creatures immediately lift their front legs above their heads to protect themselves from the projectiles. 

There is still some damage, but nowhere near what is normal for Izumi. 

“They are using the claws more like shields,” Mikumo announced over the coms. “And they seem to be sturdier than the normal claws.”

He looks at the damage from a distance, seeing a small movement on the surface of shiny material the soldier is made from. “One of the claws just shifted to smooth out the damage done by Izumi's attack, so be careful in case they can change their form even more.”

“Roger that.” Tachikawa hums. “I'll be careful. Kunichika, tell the other squads too.”

“Already on it. The closest patrols should arrive very soon.”

Beside Mikumo, Izumi frowns a bit at the little damage his attack did, before a grin appears on his face. “Well, we did come here to test this out, right?” He says as he creates two Asteroids in his hands, forcing the two Trion cubes into each other.

The process is over in just seconds, Izumi getting faster every day, before the powerful Gimel bullet tears through the air, piercing through the sturdy claws like they weren't even there. 

The first line of Trion soldiers collapses just from that, leaking out energy from every hole, but they are quickly replaced by the second line of the invaders. 

“Everything works as expected,” Mikumo confirms, even if he is sure Izumi can tell. “Looks like you improved in power again since we last ran tests.”

“Heh, I have been training a bit, you know. Now for something different.” He combines Viper and Asteroid into a Cobra, the cube splitting off into a swarm of bullets that rush through the small army in front of them, avoiding each and every claw the Marmods put up to defend themselves. 

The bullets easily pierce the cores of the Trion soldiers as they weave around the shields, and one by one the Trion soldiers fall apart. 

“Man, I wish we had found a stable way to combine two Meteor's together. That would probably help to clear out this crowd fast.” 

Mikumo can't help but nod in agreement. Combining the Meteor bullets works, but during every attempt they detonated right after, taking the blond with it during every try so far. 

And since the power was so great, even Izumi's shield couldn't protect him from the blast. He bailed out so often. 

The Trion soldiers in front of them stall with their attack, before slowly starting to scuttle backwards at full speed. 

“Oh man, they are the ones with retreat protocols implemented. Let's hunt them down before they scatter too much.” Izumi complains, jumping down from the roof to chase after them, rushing through the already destroyed ones. 

But the moment he does Osamu sees a small shift in the pile of destroyed Marmods, hidden from view where Izumi is standing. 

Quickly Osamu’s hands rush to his laptop to activate Izumi's shield, the barrier immediately flickering up to fully surround the blonde boy. 

And not a moment too late, as the left behind claws between the destroyed Trion soldiers explode in a bright burst of energy, shaking the ground and even throwing Osamu who hasn't followed off his feet. 

“Kunichika, did you catch that?” He groans out, standing up to his feet, seeing some cracks have spread through his body from the explosion. He is glad his laptop was constructed from Trion, or it would probably have broken. ‘At least Izumi is safe. His shield is sturdy as always.’ 

“Don't worry, I will transfer the info to every other team.” She ensures him, probably already sending the visual information recorded through his eyes to captain Tachikawa and the rest. 

From the cloud of dust Izumi jumps up to the now ruined building Mikumo was standing on, reaching out a hand and helping his friend to his feet, careful the already damaged Trion body isn't damaged further. 

“Nice save. I can always trust you to have my back.” Izumi says with that playful wink of his, making Mikumo let out a small laugh. 

“Just don't get too used to it. I can't join you in your next rank wars.”

“Truly a shame. It would be great to have you around.”

Mikumo feels genuinely happy to hear the praise, a wide smile on his face, but he still shakes his head. “I doubt it. I would be taken out before I even had the chance to do anything.” 

“Maybe with a full-time Bagworm? That could probably work out. You are just so good at providing a shield whenever I need it.”

“But the shields I make are created through your trigger. If I were using my own Trion, they would barely survive a hit, if that. And this kind of equipment isn't allowed in Rank wars.” He reminds the blonde, pointing to his laptop, that he uses to activate Izumi's shield. 

“Right. It was like that. Still, it's a shame.” He says as he releases another volley of Cobra bullets, arcing through the air and precisely hitting the Trion soldiers that tried to escape. 

Mikumo just follows him as Izumi continues to hunt down the Trion soldiers, testing out the composite bullets whenever he gets the chance. 

There aren't any more complications with the neighbors, and the experiment is deemed a success. Not that Mikumo had any doubts about it. 

After they finish their patrol, Tachikawa squad decides to go celebrate the success of the higher-ups recognizing composite bullets as an official and viable new combat tool. 

Tachikawa squad drags Mikumo along to the celebration before he even could think about declining, and he is pretty sure Izumi would have carried him if necessary. 

Kunichika leads them towards a small bar tucked in the side of the road, nestled between the taller buildings, and the four spent well into the late hours of the night. 

Mikumo easily found himself dragged into the by now familiar chaos that comes with this group, letting out happy laughs at Tachikawa’s bad jokes and Izumi's insane ideas, his shoulders slowly losing the tension that had built up over the last months. 

And things just felt more right and at home than they had in a long, long time.

Notes:

For the timeline I assume this takes place after Hatohara leaves Ninomiya Squad and before Yuiga joins Tachikawa squad. Also, the fact that Hatohara left before Ninomiya had the chance to ask Izumi how to create composite bullets is totally planned and didn't just happen because I messed up the timeline in my head and was too lazy to change the like 25k words I had written since then. Totally. Actually caused some interesting changes for the story.

And I havent found a name for a composite bullet of two meteors on the wiki, so I’m including that in the story, even if it exists and just hasn't been revealed yet. XD