Archive of Our Own ^beta

Chapter Text

The night was a blur to Inosuke, but he felt a lot better by the end of it. Finally getting knotted repeadly after a week of torture was bliss, especially with an alpha like Sanemi. He was rough and his stamina had no limits, Inosuke gladly allowed the pillar to use him as much as he desired until they both fell asleep, exhausted and still connected to each other.

Shinobu, however, was not pleased about them getting intimate. The next morning, she slid the door open, not caring what she saw, and demanded that Sanemi leave the room. The alpha grumbled something about it being his room, but he complied.

When he was gone, Shinobu made sure Inosuke wasn’t hurt before she sent him to clean himself. After a nice bath that soothed his aching and sore muscles, Inosuke was ordered to meet Shinobu in her office.

“You do know you could be pregnant now, right?” She said as soon as he entered.

“Yeah, but this isn’t my first time-”

“I told you to stop for a reason,” The insect pillar cut in. “I guess I should be thankful you weren’t with a stranger this time. But you remember what I told you the other times, right?”

Inosuke pondered for a second. “Uuh…”

“You won’t be allowed to fight and you’ll lose your muscle mass. It’ll take awhile for you to recover and get strong again,” She said, exasperated. “And what about the child? Do you think you’re ready to raise a child?”

“AUGH! You’re talking too much about thinking, that’s not my thing!” Inosuke exclaimed, gripping his hair in frustration. “I’ll be fine, I always am!”

“Inosuke-!”

Before Shinobu could finish, Inosuke had stomped out of the room, huffing and angrily muttering. She sighed and slumped into her chair, rubbing her temple in an attempt to calm her headache. “Shinazugawa, for your sake he better not be pregnant.”

-

About a month after leaving the Butterfly Estate, Inosuke was forced to go back by Tanjiro. “You’re acting weird and you threw up this morning, not to mention you smell off, you’re seeing Shinobu!” He declared, dragging his raging friend by the arm.

“IM FINE!” Inosuke insisted, digging his feet into the ground.

Tanjiro ignored him and dragged him up to the estate, first seeing the girls hanging up laundry to dry. “Is Shinobu here?” He asked Aoi, who sighed at the sight of the raging boar.

“In her office, she’s been expecting him.”

“What do you mean?”

“He was here during his heat, he and Shin-”

“SHUT UP, PIPSQUEAK!” Inosuke shouted, lunging forward at Aoi. She stepped back, not too scared since Tanjiro was there to hold him back. Tanjiro could smell embarrassment from his friend, which was weird coming from him.

The younger girls huddled behind Aoi, who crossed her arms and glared at Inosuke. Tanjiro thanked her and carried Inosuke inside, which enraged him more. The insect pillar stepped out of her office, smiling as usual, but Tanjiro could smell a sense of dread from her.

“He seems to be uninjured,” She noted, stepping aside to let the two in before closing the door behind them.

Tanjiro sighed and sat on Inosuke, who squirmed and yelled, his boar head tumbling out of reach. “I know, but he smells different and has been acting weird, he also threw up this morning.”

“Weird how?” Shinobu asked, kneeling down to inspect Inosuke, who gave up struggling and glared at her.

“He’s nesting, he’s never done that before. He’s tired all the time, he’s a lot hungrier, he’s also a lot more… emotional? He cried yesterday because Zenitsu insulted him, which never happens. I think Nezuko knows something’s wrong too, she’s been protective of him,” Tanjiro explained. Inosuke grunted in response, avoiding eye contact with Shinobu.

“I think I know what’s going on,” She sighed, standing up. Tanjiro looked up at her and tilted his head to the side. “I’m afraid he’s, um… pregnant.”

The boy stared at her, processing what he just said, before his eyes widened with realization. “WHAT?!” He shouted, getting off of Inosuke to kneel next to him and bombard him with questions. “Who did this?! Did you consent to it? Are you-”

“Shut up Kentaro! I’m not a baby!” Inosuke shouted, slapping Tanjiro’s hands away.

Shinobu furrowed her brows. “What are you going to do?” She asked, watching Inosuke sit up, still avoiding eye contact and reaching for his boar head. He went still and quiet for a moment, holding the boar head in his lap, before shrugging his shoulders.

“Dunno. Wait till it’s born and figure it out from there.”

“You do realize I can’t let you fight until then, right?”

“WHAT?!” Inosuke shouted. “Why not?!”

“You could get hurt! Or worse, the baby could!” Tanjiro said, grabbing Inosuke’s shoulders.

“I can just move it!” He yelled, tears of frustration welling in his eyes.

The insect pillar grabbed his hands and squeezed them. “Trust me, Inosuke, this is the last thing we want to do, but it’s for the best for you and your child,” She said, watching Tanjiro wrap his arms around Inosuke. “Do you want me to tell Shinazugawa?”

Tanjiro pulled away from Inosuke, his face contorted with anger and his hands gripping his forearms. “Did he do this?” Inosuke hesitantly nodded, blinking away tears.

“... I’ll be back,” He said, standing up and walking out the door, one hand gripping his blade.

“Tanjiro, no! Don’t kill the father of your friend’s child!” Shinobu shouted, chasing after the seething demon slayer. Inosuke sighed and buried his face in his hands.

Chapter Text

It wouldn’t be a few more months until Sanemi arrived back at the estate due to a few broken ribs. When he got there, Tanjiro was standing at the entrance, his brows furrowed and his fists clenched at his sides as he glared at the wind pillar. It wasn’t much of a surprise he was there, but it was odd he didn’t have any obvious injuries. “What’s your problem?” Sanemi snarled, curling his lip.

“You know why!”

“Still mad about your sister? It’s been a fucking year and I was doing my job, now get out of my way-”

Tanjiro yelled and charged at him, and before he could react, he slammed his ridiculously hard head against the pillar’s. Sanemi shouted out in pain and shoved the boy away, clutching his forehead as blood dribbled down his face. “What the hell was that for?!”

“That was for Inosuke!”

Sanemi gave him a puzzled look. “That boar brat? What the fuck did I do to him?!”

Tanjiro blinked. “You really don’t know?”

“Know what?!”

-

Sanemi kicked down the door, making the girls in the room shriek in panic. “So, when the fuck were you going to tell me?!” He yelled at Shinobu, who simply smiled at him as the girls ran behind her. She stood up, letting two of the girls grab her hands.

“I’ve been busy preparing for the baby, my bad.”

The wind pillar gritted his teeth, desperately trying not to lose his temper. “Where’s the brat?”

“In his room asleep, why?”

“I need to speak with him.”

“No. I don’t want you to stress him out, you can speak with him when you’ve calmed down.”

“I am calm!” Sanemi shouted, making the young girls flinch. Tanjiro ran into the room, breathing heavily.

“I’m sorry, Shinobu, I didn’t know-!”

“It’s ok, he would have found out eventually. Please go check on Inosuke.” Tanjiro nodded and left the room. Shinobu nodded at the girls to follow, so they did, walking over the broken door and staying far away from Sanemi as they could.

Once they were alone, Shinobu’s smile disappeared. “Sit, let me tend to your head” She said, pulling up a chair in front of hers before sitting.

Sanemi sighed and ran his hand through his hair before he reluctantly sat down. Shinobu pulled out a small kit from her desk and began to clean his wound. “Why do you want to speak to him?” She finally asked.

“I don’t know, maybe because he’s carrying my child. Why the fuck didn’t anyone tell me?”

Shinobu dabbed Sanemi’s forehead with medication, making him flinch.

“He didn’t want you to know, he wanted to raise the child himself. He was worried you’d claim him as your mate as well. Want me to cover it?”

“Nah, it’s fine,” He sighed, leaning back and rubbing his face. “How far along is he?”

“Ah, about thirty-five weeks, so he’s close. He’s been stressed though, being unable to fight, and he’s restless. Tanjiro has been sleeping next to him, that seems to help.”

A slight feeling of jealousy pricked Sanemi. “I see, I’m not sure if I can help with that.”

Shinobu perked up. “Actually, I think you can.”

-

The insect pillar led Sanemi Inosuke’s room, where the girls were cleaning and gathering the laundry while Tanjiro sat on the side of the bed. The window was open, the curtains fluttering in the breeze, and light shined on the rocks and flower vases that decorated the windowsill. There was a bed in a corner covered in blankets and pillow with an obvious person under the sheets.

“Inosuke is trying to sleep, he said he didn’t get much sleep last night, even though Tanjiro was with him. We changed the sheets and opened the window to let in fresh air to see if that would help,” Kiyo whispered to the two, holding some of the old sheets.

Shinobu smiled at her. “Thank you. Shinazugawa has something to help Inosuke.”

Tanjiro shot a look at Sanemi as he walked over and draped himself over the bundle on the bed. “Move, asshole,” Sanemi snapped. Tanjiro glanced at Shinobu, who nodded, before climbing over Inosuke and lightly shaking him.

“Hey, Inosuke, wake up,” He said, making the sheets stir.

Inosuke poked his head from under the covers, a sleepy expression on his face. Sanemi kneeled down to his level, which honestly hurt his ribs, next to the bed and held out his haori. “Here, you can keep this, I think it’ll help you sleep better,” He said as softly as possible. Inosuke looked at Sanemi then the haori before snatching it and retreating back under the covers. “Tch, you’re welcome, brat.”

“How about we let Inosuke rest?” Shinobu suggested. Everyone silently agreed and left, quietly closing the door. The girls left, leaving the demon slayers. “So,” Shinobu started, looking at Sanemi, “what are you going to do now?”

The wind pillar shrugged. “I need time to actually think about it, I’m just now finding out about all this.”

“Very well, I’ll inform you when the child is born.”

“You better. Also, brat,” Sanemi turned to Tanjiro, “next time you headbutt me, I’ll stab you.”

Tanjiro pouted but didn’t argue.

Chapter Text

Sanemi stayed at the estate for a few more days to recover from his broken ribs and concussion. He didn’t see Inosuke, but apparently he wore the haori he gave him often and he was sleeping better. It gave him a warm feeling in his chest, both helping the omega but also knowing he found comfort in his scent. The pillar brushed it off though, it was just their natural instincts, Inosuke didn’t want anything to do with him. 

“Hey, I’m leaving. Thanks for the help,” Sanemi declared as he walked by Shinobu’s office. 

“Of course, would you like to say goodbye to Inosuke? He’s outside right now.” Shinobu said, poking her head out of her office, but Sanemi had already disappeared. 

-

A few weeks later, Sanemi received the letter he’s been waiting for. Hashibira Kouichi was born on April 5th, five days before Sanemi got the letter. The infant had almost died, the letter didn’t go into details as to how, but luckily he survived. Inosuke was so shaken he didn’t let anyone touch Kouichi for hours, but eventually he was calmed down. 

As soon as he heard, the wind pillar made his way to the estate, which took about a week. When he arrived it was night time, and Mitsuri, Obanai, and Giyuu were there, much to his surprise. “What the fuck-”

“Congratulations, Shinazugawa !” Mitsuri beamed. “Kouichi is so adorable! You and Inosuke make beautiful babies! When are you having another one?” She asked, clasping her hands together excitedly. 

Sanemi turned red, with both embarrassment and anger. “Wait, when did you find out?!” He shouted, making the others jump.

“Tanjiro told me when he found out, so most of the time,” Giyuu stated, earning a glare from Sanemi. Why the fuck did he know before him?!

“I visited the estate when Inosuke was a few months along!”

“Kanroji told almost everyone immediately after,” Obanai said. “I don’t care, I just came because she insisted.” Mitsuri flushed and looked away from Sanemi’s angry gaze.

“ Everyone? ” 

“I’m sorry! But everything has been so gloomy lately, and babies are always a joy to talk about!” The omega squeaked, grabbing Obanai’s haori. “Wait! Are you going to claim Inosuke and get married? You should! I can plan it, it’ll be so cute!”

“Does that boar kid even know what the concept of marriage is?” Obanai asked.

Giyuu shook his head. “Tanjiro said he was raised by boars, so probably not.”

Sanemi groaned and buried his face into his hands. Great. Marriage and claiming talk, Misturi must’ve pestered poor Inosuke about it already. And Genya would find out about the kid eventually too, which was another problem he would have to deal with. “Look, I’m just here to see my kid and check on Inosuke, we can sort this out later-”

“Oh, you’re here,” Shinobu cut in, stepping outside onto the porch with Kanao by her side. “I’m going to speak to the others, but Kanao can take you to Inosuke and Kouichi if you want,” She said, motioning to her tsuguko, who smiled at Sanemi.

“Uh, yeah, that’d be nice… they doing ok? That letter was kind of concerning”

Shinobu grinned. “Perfectly fine. Kanao, please take Shinazugawa to see Inosuke and Kouichi.” Kanao nodded and began to walk back inside the estate. Sanemi rushed to follow her, tripping on the stairs, but caught himself and caught up with the girl. 

Mitsuri went to follow, but Shinobu grabbed her haori. “Aw, I wanted to see Shinazugawa meet Kouichi,” She pouted.

“There’s already a lot of people seeing Inosuke and Kouichi, let’s not stress them out.”

-

The room was too crowded for Sanemi’s liking. There was the rest of butterfly girls, Zenitsu, Tanjiro, and Nezuko, which made Sanemi’s blood boil. Inosuke was sitting up in his nest of blankets and pillows, and his boar mask of course, wearing the haori he gave him, his eyes half lidded with exhaustion. His son- their son- was cradled against his chest and giggling as Nezuko and Tanjiro played with him. He had the cutest, chubby baby face, crowned white hair that faded to blue, and bright green eyes just like Inosuke. Sanemi was awestruck. How did two assholes like them make something so… precious?

“You’re the alpha that got Inosuke knocked up?!” Zenitsu shrieked, pointing at Sanemi, which made everyone look at him. “You’re scary too! This poor child is doomed-!” Aoi slapped upside the head. 

“Shut up! We just got Kouichi to stop crying!” She whispered angrily. 

Zenitsu whimpered and cupped his head, but stayed quiet. “There’s too many people in here, everyone fucking leave, especially the demon brat,” Sanemi ordered, shooting a glare at Nezuko. Nezuko pouted at him but left, a trembling Zenitsu, a seething Tanjiro, and the butterfly girls following behind her.

Inosuke finally looked up at Sanemi, clutching Kouichi tighter against his chest. “Did you come here to claim me?” 

“If I wanted to claim you, I would’ve done that last time I was here. I just wanted to meet Kouichi,” Sanemi responded, slowly walking up to the nest and sitting on the edge, watching the omega tense and shift nervously. Kouichi stared up at his dad and cooed, making Sanemi’s heart melt. “Kouichi, huh? You happy all those loud assholes are gone?” He mused and leaned forward to lightly pinch his chubby cheek, watching Kouichi giggle in response. Inosuke stayed uncharacteristicly silent, watching the two interact. 

Gods, he looks so miserable and tired. “Can I hold him?” Sanemi asked, holding out his arms. Inosuke stared at him blankly, before he hesitantly nodded and placed Kouichi in Sanemi’s arms, making sure he was holding him correctly. 

Kouichi was so warm and tiny in his arms, it was unreal. A sudden realization overwhelmed Sanemi, that holy shit- he was a dad now. For the first time in awhile, he felt tears welling in his eyes. He grumbled and wiped them away, Kouichi watching him with interest. 

“Fuck, sorry I-” He looked up and saw Inosuke slumped back against his pillow, his eyes closed and his chest slowly rising and falling. Sanemi gently placed Kouichi on the nest and moved Inosuke into a more comfortable sleeping position, lightly petting his head after he was tucked in. Kouichi began to whine and reached out to his dad. 

“Oh fuck, shh, your ma’s sleeping,” Sanemi whispered, wiping his eyes and picking the squirming infant up again, immediatly calming him down. “I’d take you outside, but if your ma woke up and you were gone, he’d flip and kick my ass.” 

The baby gurgled and shoved his fist in his mouth, earning a small chuckle from his dad. “Oh, is Inosuke asleep?” Tanjiro asked, peeking into the room.

“Yeah, you better not wake him up.”

“I won’t, I just wanted to check up on him,” The alpha said, sitting next to Sanemi and petting Kouichi’s cheek. “Did you decide what you wanted to do?”

“...No. What does the brat want to do?”

Tanjiro looked over at Inosuke, his mouth shaping into a small frown. “He wants to raise him, but he also wants to fight demons. Right now we’re trying to just keep his mind off it and help him relax. After Kouichi almost died, he’s been really attached, so I think he’s going to focus on raising him first while also regaining his strength.”

“How the hell did he almost die?”

Tanjiro shrugged. “I’m not sure what happened, when he was born he wasn’t screaming, but Shinobu saved him. Guess he had something that made him unable to breathe. Poor Inosuke was so worried, we had to restrain him while Shinobu helped Kouichi. Other than that he’s pretty healthy.”

Kouichi yawned and stretched his tiny arms, thumping his fist against Sanemi’s chest. “Oops, it’s way past his bedtime, I’m surprised he stayed up so late, I guess he was just excited to meet so many new people.”

Sanemi placed Kouichi in the nest, watching him snuggle up against Inosuke and cling to the haori, almost immediately falling asleep. The alpha watched them for a bit, watching their chests rise and fall, wanting nothing more than to claim Inosuke, sinking his teeth into his scent gland and marking him as his. He could start a family again… He stood up, looking at them a bit longer, before turning to leave, blood spilling into his mouth as he bit into his cheek. 

He had to get out of there before he did something he would regret. 

“Ah, Shinazugawa-!”

“I’ll visit sometimes, but it’s obvious the brat wants nothing to do with me. I already made his life miserable, I’m not gonna make it worse.”

The younger alpha fell silent and watched Sanemi leave, not exactly knowing how to respond to that. He left through the back, not wanting to run into the other pillars

Fuck his stupid instincts.