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That Same Smile

Summary:

“Dynamight!” Someone shouted, running towards him and immediately tugging on his arm to lead him to the commotion.

“Hey! Chill out!” He shouted, but his heart completely stopped when he saw a pile of clothes on the floor. A pile of clothes that was his best friend’s hero costume.

“Eiji--Red?” He asks, fear clear in his voice.

An older woman comes towards him, and he grows confused as to why he's being handed a small kid, wrapped up in a jacket, with jet black hair and red…

“Eijiro?” He asks again, bittersweet relief flooding down his chest.

--OR--

Eijiro gets hit with a quirk that turns him into a kid. Can Katsuki take care of him while also navigating the hurt feelings between him and his best friend?

Notes:

(See the end of the work for notes.)

Work Text:

Call him paranoid. Call him an overthinker. But he could feel it. 

He was out on patrol, by himself; he might fucking add. And he knew someone was watching him.

It was a simple work study mission. Aizawa had sent him out to do some recon on some quirk accidents that had been happening more than not. Some juvenile asshole whose quirk kind of worked like Monoma’s. Jack of all trades and shit. He had almost any quirk he could think of and was near impossible to catch, apparently.

But like hell if Katsuki was gonna be part of that statistic. He was gonna catch that bastard.

And if that bastard was the one watching him…he was gonna get his ass handed to him and then some.

He turned the corner, taking out those stupid binoculars a first-year support course kid insisted he have. 

He scoffed when he saw nothing. Typical. Gear was always useless. He relied on his skills and stealth. He tossed those shits back in his pack, tempted to just chuck the whole thing in the alley. 

But that's when he felt it. Eyes burning on his back. 

He clenched his jaw, moving out of the alley because he wasn't stupid and he knew it now. 

Someone was behind him. Coming towards him. 

He readied his hands, hearing the sparks and pops. He was gonna get whoever this was.

He swallowed, hearing nothing, and then he felt a breath on his neck. 

He saw white, and an explosion rang out, aimed at…aimed at fucking…?!? 

What the…fucking asshole! 

 

“What the hell, Kirishima? What are you doing here?!” He shouted, wanting to blow up the bastard’s face again.

Kirishima coughed, half of his face hardened, and waving his hand in the air.

“What the hell to you, man?” Kirishima half coughed, half laughed.

“Why were you sneaking up on me like some damn creeper?!”

“Dude. No, I wasn't. I called your name like ten times.”

“Bullshit.” 

“You okay, man?” Kirishima reached out, about to place his hand over his chest, but Katsuki swatted it away. “Aw, still pissed at me? Come on, Blasty.”

“Shut up. I'm fine.” But, just for good measure, he checked his heart himself. Yeah. Whatever. He was fine. He didn't need Kirishima checking on him. Or sneaking up on him like some idiot. And he was a little pissed at him still. Okay. A lot pissed at him. 

Ugh. Fuck. Okay. Maybe he was getting too paranoid. But the asshole still hasn't answered.

He glared at him, and luckily, his supposed best friend knew him well enough.

“Aizawa sent me. Thought you could use some company.”

“Well, I don't.”

Kirishima grinned wide, looking so stupid with half his face covered in soot. “Aw, yeah, you do.” 

He figured he wasn't gonna win the eventual argument, so he just sighed. “Whatever.” 

“So what's the plan, Great Explosion Murder God?”

“Stay out of my way.”

Kirishima laughs, “You're so funny, man. Want me to scout the opposite side? Or did you want to go aerial?”

“There are no stairs around here outside the buildings. You can't go aerial, idiot.”

“Wow, chill out, dude. You're scary pissed at me.” Kirishima says this like it's some joke. Like he didn't just practically end their friendship last night. But he couldn't let this ruin the mission. 

He rolls his eyes, “Guess you take one side and I take the other.” Couldn't hurt.

“Did you turn on your comms?”

He looks at Kirishima with clear confusion, “Comms?”

“Oh! That's why…” his sentence fades. “In your gear bag?” He gestures to it, and he notices Kirishima has one similar.

“No.” 

“We can link them together. So we’re always with each other. How manly is that?” Kirishima says so genuinely that he can't even make fun of it.

 

He reaches into his gear bag, pulling out a small black case where he assumes the comms are.

Kirishima, clearly more versed in all the shit they have, links them up together, and soon they're on their way.

“Wait! Test if you can hear me.” Kirishima says, stepping away. 

He hears one, then two beeps in his ears. Then static.

“Can you hear me, Murder God?” Says the staticky, raspy voice of his best friend. These comms are good; he won't lie. It's almost like he was right in his ear. 

“I got it, Red.” He says back.

“Cool! I go left, you go right?”

“Sure.” He shrugs.

“Alright, see ya!” Kirishima waves from where he's at. And in the setting sun, the reds in his hair playing with the sunbeams…Kirishima looks kind of…pretty.

But that was a thought for later. Right now, it was getting that villain’s ass.

 


 

This felt fucking useless. It's been about two hours and nothing. Absolutely nothing. He had a feeling the villain heard more people were on his ass and hid. Ugh. So much for catching him.

But him? He wasn't gonna call it quits. Shitty Hair could go home for all he cares, but he's not giving up unless he gets something.

“Red. You gonna call it quits soon? I'm gonna go around for another hour.”

Two beeps came through his comms. “Nah, man! I'm with you till the end. Why don't we meet up and take a break for a bit? A nice old lady recognized me and bought me some snacks. Wanna share?” 

He sighed, “Sure.” Stupid, cheesy-ass idiot and his dumb sayings and his old ladies.

“Cool! Meet up by the konbini? I'll get you a drink.”

“Yeah. I'll be there, Red. Thanks.”

Three beeps indicated that Kirishima was out, and he started heading towards the konbini nearby. 

 

As soon as he started walking, Katsuki started to feel that thing again. Maybe having Kirishima on the “other end” was comforting to him. Hell. Sue him. Eijiro was his best friend for a reason. They took care of each other. They always did. Even with the small things like buying a drink or telling Kirishima to get off his ass and stop moping around after a bad day in training.

He's not ashamed to admit that he'd do anything for him. He knows Kirishima would do the same.

The hair on the back of his neck rose as he got closer to Kirishima. He felt tension. Thick in the air. People were running around, hiding, a slight murmur from the crowd.

At the sound of the first scream, his body went into adrenaline mode, and as quickly as he could, he went into the chaos of the crowd.

He quickly touched his comms, “Red? You seeing this?”

His heart skipped a beat when he didn't hear two back. Bullshit petty argument aside, he couldn’t fucking function if…

“Red?” He asked again. “Kirishima. You there?” He could feel his breath getting heavy. And he couldn't get that way. 

But the crowd was crazy, and it was not even a second ago when Kirishima was talking to him. What the hell could happen so fast?

He saw a blur of bodies coming towards him.

“Dynamight! My boyfriend! I can't find him!” Shouted a random civilian, tears streaming down her face.

Before he could even answer, a man came up to him with the same terrified look.

“My daughter. I can't find my daughter. Please, please help me.”

People started crowding him, and he didn't know what to do. Fuck. This was overwhelming. 

But. He was Dynamight. He could do anything.

 

“Hey! Extras! Give me a second! I can't help you all at once!” He shouted.

He snapped all the people back to attention. And he sighed.

“Let me go find Red Riot, and we can help you. Just line up here, alright?” 

The crowd looked stunned, so he yelled again, “Alright?!”

Murmurs of agreement sounded out, and he went towards the konbini Eijiro promised to be at.

Another crowd of people was by the entrance of the store, all surrounding something on the sidewalk.

He walked towards them, hoping Kirishima was nearby. He knew his presence would be much more of a comfort than his.

“Dynamight!” Someone shouted, running towards him and immediately tugging on his arm to lead him to the commotion. 

“Hey! Chill out!” He shouted, but his heart completely stopped when he saw a pile of clothes on the floor. A pile of clothes that was his best friend’s hero costume.

“Eiji--Red?” He asks, fear clear in his voice.

An older woman comes towards him, and he grows confused as to why he's being handed a small kid, wrapped up in a jacket, with jet black hair and red…

“Eijiro?” He asks again, bittersweet relief flooding down his chest. 

“We found him underneath Red Riot’s hero costume.”

He takes the kid in his arms, and the scar on his eye is undeniable.

“I got you, Red. You're okay.” He whispers, holding him close as the poor thing has tears brimming in his eyes. 

“Are you a hero?” Kirishima asks, voice so small and squeaky. 

He smiles despite it all, “Yeah, sure am, kid.”

Kirishima’s mouth wobbles, and he buries his face in his neck.

“Can you help me find my mommies?” 

Oh crap. His heart.

“I'll help you all I can.” He promises, hugging his best friend right back. 

 


 

As soon as Aizawa was on the scene and the pros and police got a hold of the situation, Katsuki was sent back with Kirishima in his arms. He already felt the onslaught of attention they would get from just walking in, and he didn't think Kirishima would appreciate it. He was already overwhelmed and confused. 

“Is it true what Mr.Eraser said?” Kirishima asked in the back of the car that Aizawa had sent for them.

Katsuki has never been one to be good with kids. Hell, he's not good around people. But there was always something about Kirishima that felt like second nature. And right now, that urge to protect all that preciousness and pureness that was Kirishima was overwhelming. He wished he could just run up to his room and hide. But that would make things even worse. Poor thing had already sobbed his eyes out at the fact that they wouldn't be going back to his “mommies.” What inconvenient timing for them to be out of town. But going by what Kirishima has told him before, they'd drop anything for him in a heartbeat. 

Katsuki was determined, however. He would handle this. He’s got this.

“Is what true, kid?”

“That I'm going to a hero school? And that I'll hang out with them all day?”

He smiled, “Yeah. It's true.”

Kirishima's little eyes lit up, “Really?! Is Crimson Riot there?!”

He chuckled, “Nah, kid. He's off saving someone somewhere. But uh…my best friend has some pretty cool Crimson Riot shi-stuff I can show you.” 

“Really?!” Kirishima said again, bouncing in his seat. He pouts, then, “I bet he's a much cooler fan than me.” 

Ouch. Dammit. How the hell was he going to handle a little version of his insecure best friend? Isn't this the age for their important development or whatever? What if he said something and it fucked up older Kirishima? 

“Well, my best friend is pretty cool, but you're pretty cool too.”

Kirishima beamed, tiny stars in his eyes, “You think I'm cool?”

His heart warmed. “The coolest.” He reached down to ruffle Kirishima’s hair and smiled.

“I'm sleepy, Dynamighty. Can I go to sleep?”

Be still, his goddamn heart. Dynamighty? Like hell if he was gonna correct that. 

He frowned, “We’re almost there. How about you rest your eyes instead, and you can take a nap on my best friend's bed when we get there, yeah?”

Kirishima’s forehead crinkled up, “Will he get mad?”

“Nah,” he almost laughed, “He loves helping people out. He thinks it's super manly.”

Kirishima’s face lit up like a million little stars, “Helping out is manly!” Kirishima laid his head back, bringing up his feet on the seat and pouting, “Do you have a blankie?” 

Dammit. He didn’t. 

“Sorry, kid. I don’t.” He frowned right back. 

“That’s okay! Thank you!” 

Katsuki chuckled. Thank you? For what?

“You’re welcome.” He said and watched as Kirishima got himself comfortable, curling up in a little ball on the seat. He looked so small, so precious, that Katsuki would do anything to protect him. 

 


 

He never knew little Kirishima was so shy, but he buried his face in his neck as he carried him out of the car and to the dorms. He wouldn’t expect it from his best friend, who was normally so out there and fucking loud. He always pushed Katsuki to do things, made sure he was included in the inane conversations his friends had, and made him a part of things. But it also kind of did make sense. Sometimes, when the idiot brigade was being too much, he’d notice that Kirishima would get quieter. If a day were too damn much, he’d hide away in his dorm, only inviting Katsuki in to…hang out and shit. 

Katsuki sighed, thinking of the last time they hung out. Just last night, when Eijiro yelled at him for…

Ugh. Whatever. He can’t think about their stupid fight right now. He needs to take care of present Kirishima. 

Present Kirishima, who was gripping onto his hero costume for dear life. He was glad Aizawa had the foresight to bring him some of Eri’s old clothes, or the poor thing would be even colder than he was in the car, just wrapped up in that jacket. He looked kind of funny in all those cat-patterned things, but he knew his best friend would get a kick out of it. 

“Damn kid, you got a strong grip.” He decided to say, adjusting Kirishima in his hold. 

“I’m sorry, Mr. Dynamighty. I miss my mommies.” Katsuki felt Kirishima’s nose rub against his collarbone, and his heart warmed that his best friend still had that habit to this day. When they would hang out on those bad days, Kirishima would do the same when he was on the verge of tears. 

“It’s alright, kid. I’m sure your moms miss you, too. Don’t be sorry.” He didn’t want to tell him not to cry. 

“Will they like me? The heroes?” Kirishima asked. 

“Of course, they’d be ass--mean not to.”

Kirishima picked up his head, smiling at him. “Were you gonna say a bad word, Mr. Dynamight?”

“Nah, I don’t know what you heard.” He smiled back. “You ready to go in?”

Kirishima was back to shy, a blush on his face as he shook his head, “I’m scared.”

Katsuki thought about what to say, something he knew that Kirishima believed to his core, “Hey, you know being scared is super manly.”

“Yeah?” Kirishima said, his eyes lighting up.

“Yup. My best friend told me that.” He teased, starting to walk closer to the entrance. 

“Can I meet your best friend, Dynamighty?”

He made a show of pouting, “He’s out on a super badass mission right now.”

“You said a bad word!” Kirishima exclaimed, making Katsuki chuckle. 

 

Ugh. Okay. He knew people were gonna freak out seeing a little Kirishima. He knew that maybe him yelling at them to fuck off would probably scare the poor thing. He opened the door with a sigh, and Kirishima immediately hid back in his collar.

And, of course, the room erupted in squeals.

“Oh my god! Blasty! Who is that?!” Ashido screamed, running up to him right away.

“Dynamighty? Who's that?” Kirishima’s face felt warm, and he wanted more than anything to run up to his dorm and hide him.

“It’s my friend Ashido. She's a hero.” He whispered. 

“Did you find him on your mission? Where’s—”

Katsuki gave her a look, bringing a finger to his lips.

“Kirishima?” Ashido mouthed, eyes widening.

He nodded, holding the kid tighter.

Ashido’s face immediately softened, and she smiled.

“Hey there! What's your name? I'm Ashido.” 

“Wanna say hi, kid?” Katsuki asked, shaking him a little. 

Kirishima came up from his collar, eyes rimmed with tears.

“Hi. I'm Kirishima. I'm cold.” 

Ashido chuckled, “Aw, I'm sorry, cutie pie. Why don't you wait here with Bakugo and I'll get you a blanket?”

Kirishima shook his head, “I wanna nap.” 

“Wanna go up to my best friend’s room and see all his Crimson Riot stuff?” Katsuki asked. 

“Hey! Who's the kid? Awww! How cute! He looks just like—” Kaminari started, but was immediately shushed by Ashido.

“Can we go see the Crimson Riot stuff, Dynamighty?”

He smiled, not caring if anyone would give him shit for it. “Sure.”

 

Kirishima hugged him tight again as they went up to the elevator, and the ride up to their floor was silent. 

“Tired, kid? You've had a big day.”

Kirishima nodded, sniffing, “I miss my mommies. They know how to tuck me in.”

Katsuki’s heart ached at that. “My teacher, Mr. Aizawa, is going to call them. Okay? But is it okay if I take care of you for now?”

The little version of his best friend nodded, and he yawned.

“Can I see the Crimson Riot stuff later? I'm tired.”

“Of course.” He chuckled.

“Can I sleep over in your room?” Kirishima looked up at him with those puppy dog eyes of his, and they were even more lethal as a kid. He'd give his best friend the whole entire world. 

“Sure.” 

He brought Kirishima into his dorm, his arms admittedly getting a little tired from holding him up for so long.

Katsuki sat him on his bed, having the brain to text Pinky and them right after if they could go grab Kirishima some actual clothes and food. 

Kirishima’s eyes started to close as soon as he settled on his pillow, funnily enough his own, and he tried his best to tuck him in and all that like his moms probably would.

“Night, Kirishima.” He said, ruffling his hair as his breathing grew heavier. 

“Night, Dynamighty,” Kirishima said quietly.

 

He walked to his desk, letting himself exhale as the emotions of the day finally hit. 

Holy literal crap. 

What was he going to do? 

How long was this quirk going to last? 

Can he even take care of a kid right?

Shit. Fuck. He can't freak out. 

 

He took a deep breath, going into their stupidly annoying group chat to text Pinky and them.

 

To: Stop Muting Us Blasty!!!

 

KATSUKI: Hey. Come pick up some money. Kirishima needs clothes and food and snacks and shit. Can't be wearing those stupid cat clothes.

 

DUNCE FACE: Only if you let us hang with baby Kirishima :) 

 

PINKY: Pretty please :)

 

TAPE ARMS: With a cherry on top :)

 

Katsuki sighed. He should've expected this. Some help wouldn't be too bad, he guesses.

 

KATSUKI: Fine. But he's napping. So be quiet when you come in.

 

DUNCE FACE: We got it, Blasty. Don't worry about money. 

 

KATSUKI: No. 

 

TAPE ARMS: Yes. 

 

KATSUKI: You better come over here.

 

Katsuki put his phone down, leaving it at that and exhaling again. 

Maybe he should get in a nap, too. He doesn't even know how energetic Kirishima would be when he wakes up. According to the stories from his moms, he was an active kid. He hopes this quirk won't last long. But, as long as Kirishima was here with him and he had his moms on speed dial, and his own Ma at that, he'd be okay. He could fucking do this. 

He just needs a nap first.

 


 

He doesn't know when he made the transition from his desk chair to his bed, but he opened his eyes to see little Kirishima sitting between Kaminari’s legs and holding a big plush shark. The lights were off, and both Kaminari and Kirishima seemed entranced in the movie playing on his laptop screen. Some run-of-the-mill cartoon movie that's been popular lately. 

Both Ashido and Sero were on the floor, watching the movie absentmindedly, but mostly watching Kirishima. There were bags of things on his desk, snacks and a bag full of clothes. He doesn't know why the hell they bought so much, but whatever. He doesn't even remember them coming to pick up money like he said.

“Hey! Look who's awake, buddy!” Kaminari said, tickling Kirishima’s stomach to get his attention.

Kirishima looked like a completely different kid after his rest, eyes lighting up and a wide smile appearing on his face. He hadn't noticed yet, but only some of his teeth were sharp. Halfway straight and halfway pointed. 

“Good nap, Blasty?” Sero asked.

He nodded. Stretching his arms and groaned as he realized he had fallen asleep in his hero costume. That meant a change of sheets. 

“Dynamighty! You're awake!” Kirishima said like it was the best thing in the world.

He watched as he scrambled out of Kaminari’s arms, and he gave an exaggerated pout.

“Man, once the favorite, always the favorite.” Kaminari chuckled. 

 

Kirishima walked up to the bed, holding up his arms, and Katsuki was quick to pick him up.

“Hey. Sleep good, kid?”

Kirishima didn't respond, but instead gave him a tight hug on his neck.

“Strong grip.” He chuckled. 

“Dynamighty! Your friends are so cool! Look! Mina gave me a shark! I love sharks!” Kirishima beamed.

Oh crap. How was his stupid sappy heart gonna handle this?

“Yeah?” He asked.

“Wanna play with it with me?”

“I gotta go get dressed and sh-stuff first. Okay?”

Kirishima frowned, “Were you gonna say a bad word again?”

He smiled, “Nah.”

Kirishima pouted, “Are you gonna take long, like your nap?”

He shook his head. “Nah. You can even come to my closet to help me pick out clothes.”

“Okay!” Kirishima hugged his neck tight again, and he had to laugh at how completely different he was. 

He was glad he wasn't scared and sad anymore. Back to the Kirishima they knew. 

Kirishima, of course, picked out something red for him to wear. A t-shirt he had left in his hamper way back when. 

Kirishima was changed too, in some small basketball shorts and a shirt with a shark on it. Leave it to Pinky to pick out a theme.

 

“Are you hungry, sweetie?" Ashido asked, opening her arms for Kirishima to run into.

“Can I have squid noodles?” Kirishima asked as he sat on her lap. 

Ashido laughed, “Squid noodles? What's that, cutie? Like the flavor?”

Katsuki rolled his eyes. How the hell could she not figure it out?

“You mean sausage and ramen noodles?”

Kirishima gasped, “Did you ask my mommies?”

“Nah. My best friend likes to eat that stuff sometimes.” 

Sometimes when Eijiro was feeling homesick, he'd cut up some sausage and mix it with his ramen noodles. Only the cheese kind. Sprinkle some nori on top. He'd always offer him some, but that shit didn't look appealing in the slightest. 

He assumed the squid part was how his moms used to cut it up for him. He knew he had the exact noodles Eijiro liked in his cupboard, and Eijiro always had shit like lunch meat stocked in the fridge for a quick snack.

“Bakugo can cook it for you!” Kaminari said, “Right dude?”

Katsuki nodded, “But you have to stay here, alright?” He didn't want people to be freaking out about him in the common room. He didn't want him to get scared and sad again. 

Though, it seemed his words were a mistake anyway as Kirishima's eyes immediately filled up with tears, his lip wobbly.

“I can't go with you?” He started sniffling, and damn his poor heart. Poor kid. He had no idea Eijiro was like this as a kid. But it made sense. He was practically in a room with strangers. 

Katsuki clicked his teeth, going up to Ashido to bend down to his level.

“Someone has gotta protect my friends here. Think you're the hero for the job?”

Kirishima pouted at him, “I'm not a hero. My quirk is not that cool.”

“Hey. Don't say that. You know, my best friend has the exact same quirk, and it's the most badass thing ever.”

His eyes lit up with a million stars. The same way Eijiro looks when he'd tell him he's making them steak bites for dinner.

“Really?”

“Really. So, you promise you can take care of my friends while I go cook your squid noodles?”

Kirishima nodded quickly, a look of determination on his face. 

He laughed, ruffling up his hair before standing.

“Wow, Blasty. Didn't know you were so good with kids. Cute!” Kaminari said. 

He rolled his eyes, and when Kirishima wasn't looking, he flicked him off.

“Ah! Rude! It was a compliment!” Kaminari pouted.

Noting that Kirishima was settled back in Pinky’s arms, he waved goodbye, taking the rest of the snacks and heading to the common room.

 


 

Making Kirishima his “squid noodles” was quick work. He just cut up some sausage the way he saw online, made his ramen the way he liked it, and cut up a plate of some fruits and little cheese crackers that were in the groceries. 

He went back to his dorm with a tray in hand, holding a juice box in the other. It was kinda funny feeding him so little, considering that Eijiro takes food off the pan when he's cooking. 

Katsuki wasn't expecting the scene when he walked back into his dorm, and his heart almost broke. Little Kirishima was in tears, Sero holding him in his arms and rocking him back and forth. Sero had a lot of little cousins, so he was pretty used to kids. 

“You see, look! He's right there, Kiri!” 

Oh crap. He's crying because of him? 

“Dynamighty?” Kirishima’s little voice said, and he immediately went to his desk to put the tray down.

“Hey, kid. What's up?”

 

Sero got up, taking Kirishima in his arms to transfer to his own. Kirishima was hiccuping, his nose red and his eyes even redder.

“Hey. What's wrong?” He whispered.

“I-I missed you. I miss my mommies.”

He clicked his teeth. He didn't really know how to respond, so he said, “I missed you too, kid.”

Kirishima hugged him close again, body shaking with tears.

Ashido came up to the two of them to rub Kirishima’s back.

“He started crying a couple of minutes after you left.”

“Hey. Don't you want your squid noodles? I made them special for you.” He said.

Kirishima nodded, frowning at him.

“Okay. But you have to stop crying to eat them, okay?”

“O-okay.” 

“Okay?” He asked.

“Can you help me with my chopsticks like my mommies?”

He chuckled, “Sure, kid.”

 

He carried Kirishima back to the middle of his room, putting him in Sero’s lap, and came back with his tray.

Kirishima gasped, “Strawberries! I love strawberries!”

“Really? That's cool!” Ashido said, smiling.

“What do we say to Bakugo, Kiri?” Sero asked.

“Thank you, Dynamighty!” He shouted with a smile. 

Kirishima went for the strawberries first, of course. Then the crackers. Ashido was more than happy to twirl the noodles around his chopsticks, and Kirishima pouted and said he “wasn't a baby” when she tried to feed him.

Katsuki chuckled, glad he seemed to be in better spirits, and watched as he devoured his whole meal. 

“Can I take a nappy, now?” Kirishima asked.

“You gotta wait till your food goes down first,” Sero said, getting up to clear his tray. 

Kaminari frowned, “I'm kinda hungry, too.”

“Order food. My treat. For all of us.” Katsuki demanded.

“Really?” Kaminari beamed, “Thanks, rich boy, Kacchan!”

He rolled his eyes. “Shut up.”

“We’ll go clean up the kitchen and order food. Text us what you want?” Ashido asked.

He nodded in response.

 

Despite what Sero said, Kirishima was already dozing off. Always one to nap after a good meal.

Kirishima pushed himself up from where he was sitting as the room cleared, and he yawned as he settled between his legs.

“I'm tired, Dynamighty,” Kirishima said quietly.

“Yeah? Want another nap?”

Kirishima nodded, crawling into his lap, and Katsuki chuckled. He rose with Kirishima, putting him on his bed, and smoothed the hair off his forehead like his Ma always does for him.

“Will Sero get mad at me?”

“No. He just doesn't want your stomach to hurt.” He explained.

“Oh. My tummy won't hurt.” Kirishima said.

He watched as Kirishima settled into the bed, so small compared to his tank of a best friend who'd basically take up the whole bed. He'd take up the whole bed, and Katsuki would be left with a sliver sometimes, but he'd always remedy that by pulling him close.

Katsuki sighed. He knew Kirishima was right there, but he missed the shit out of Eijiro. Even after their dumb fight. A stupid fight that shouldn't have even happened in the first place. 

Kirishima dozed off quickly, and an idea popped into his brain. He knew Eijiro had this old plush that he loved the crap out of that was always in the middle of his bed.

He snuck away as quietly and quickly as he could, and sure enough, his little plush bear was sitting with its dumb little t-shirt on his bed. Eijiro loved dressing the thing up.

An ache filled his chest as he took in Eijiro’s dorm. And again, he knew he was in the next room, but he couldn't help but miss his goddamn best friend. 

And as much as he’ll miss little Kirishima, he hopes that this stupid quirk wears off soon.

He went back to the room, and sure enough, Kirishima was completely knocked out. He chuckled, glad even this small he was a heavy sleeper. He went to the bed, moved his little arm up carefully, and placed the plush there.

He laughed silently as Kirishima gripped it tight, just like he always would be when he'd find him sleeping on his own.

Ugh. Crap. He needs to stop thinking of his best friend. 

On one hand, he was supposed to be pissed at him. On the other, he had to take care of his quirked best friend. He had no room to miss him.

He went back to his desk chair, getting his laptop from the floor and putting on a movie on silent. 

He got a text that asked, “Food?” From Denki a second later with a menu.

He picked whatever for himself, also adding on something kid-friendly for Eijiro. 

He got a thumbs up back.

Well, nothing better to do than wait for his food. Wait for Kirishima to wake up. Wait for his best friend to get back. Wait for his stupidly insecure best friend to come to his senses and realize that…

That Katsuki loves him more than anything.

 


 

It's funny how little kids were. Because even though he had told Pinky he “wasn't a baby” earlier, Katsuki was sitting with him in Sparky’s dorm, feeding him his rice and tempura by hand.

“I just think someone has a favorite.” Ashido singsonged in his ear.

Every time Katsuki would take a bite of his own food, Kirishima would look at him hopefully, and Katsuki would sigh and feed him another bite.

He had to laugh at how red Kirishima got in the face when he insisted he could handle his spicy food. He didn't ask for more of his after that. 

When they were done, Katsuki handed Kirishima the cookie that Denki had gotten him, and his eyes lit up.

That he could eat on his own, apparently.

 

His phone buzzed in his pocket, and the call was from “U.A” so he knew it had to be Aizawa checking in.

 

Hey. How is he doing?” Aizawa asked as soon as he picked up. 

Luckily, Kirishima was distracted by the cookie as he answered.

“Okay. He's fine.”

That's good. Just came back from the infirmary with the other civilians. Not all kids. Some teenagers, some babies, some elders. I say you got lucky.”

“All quirked different?” He asked.

Aizawa hummed his confirmation, “Can't get a read on the quirk, but it seems that they believe it should wear off in a day. Gonna go back out to try to find the villain.”

“You should bring that copycat bastard. Maybe he can.” He suggested.

Good thinking. Tell me if you need anything. Should have some more of Eri’s old clothes.

“We're good with clothes.”

Okay. Gotta go. I'll check in later.” Aizawa said, hanging up the phone without prompt. 

 

“Aizawa?” Sero asked as soon as he put the phone down.

“Yeah. Said we got lucky. Some people turned into babies and old people and shit.”

“Wow. I guess we did.” Sero said.

“Any word on how long this will last?” Kaminari asked.

“Said a day.” He shrugged.

He looked at Kirishima, who was a mess of crumbs and chocolate. A bittersweet feeling stirred up in his chest. One he couldn't explain. 

“I'll miss him, that's for sure. But I'll be glad to have him back.” Kaminari said with a frown.

“Yeah.” He agreed. 

“Kiri! Can I help clean your face and give you some cozy pajamas to change into?” Ashido asked.

Kirishima nodded, “Okay.” He finished the rest of his cookie, holding up his arms for Ashido.

She chuckled warmly as she picked him up, hugging him close. “You're so cute!” She squealed.

“No, I'm not! I'm a big boy.” Kirishima frowned. 

“Aw, but you can be a big boy and cute,” Kaminari said. “Being cute doesn't make you any less of a big boy.” 

Kirishima seemed to find joy in that, eyes lighting up.

“Really?”

“Yeah! Really, really, cutie pie!” Kaminari said with a big grin.

“Cool!” Kirishima said, making Ashido laugh and hold him tight again.

She took him out of the door and presumably back to his dorm, where all of the clothes were.

He doesn't know what they'll do with all of his clothes when he's back to normal, but he guesses they can donate them.

…or keep them for Eijiro to dress up his dumb little bear.

 

He finished up the rest of his food quickly, not realizing how hungry he was, and got up with a sigh.

“You’re leaving?” Kaminari asked.

“Yeah. Gonna go back to my dorm.”

“Aw, I wanted to see if Kiri wanted to play a video game.” Kaminari frowned.

“I didn't say you couldn't.” He gave him a look of confusion.

“Trust me, Blasty. He can't if you're not here.” Sero chuckled.

“What the hell, why?”

“You didn't see the uh…tantrum he pulled when you left to make him food,” Sero explained. 

“I was gone for like 15 minutes.” He rolled his eyes.

“And how does regular Kiri act when Bakugo is gone, Hanta?” Kaminari asked.

“Mmm…gets super pouty and sad until he comes back.”

“What the fuck, no he doesn't.” He scoffed. 

“Oh trust me, you've never been there. He's so mopey.”  Sero said.

“I guess as a kid it's like magnetized by ten,” Kaminari said.

“It's magnified, you moron.” He rolled his eyes again. “Ugh. Fine. I'll stay here.”

“Yay!” Sparky said like the idiot he was. 

 

They cleaned up their trays, and by the time Ashido came back, Kirishima was all cleaned and dressed, clutching his bear in his arms. He had to laugh at how Ashido had put up his hair. Little clips to keep it off his face.

“Hey Kiri! Do you wanna play a game with me?” Kaminari asked, holding up a controller.

Kirishima’s eyes lit up. “Yeah! Can Riot play too?”

“Yeah! Of course!” Kaminari laughed. 

Kirishima went to Kaminari, and he was glad the kid was happy for now.

Even though he was feeling tired again, he stayed there and watched until the late afternoon reached night, happy he was able to keep Kirishima safe.

 


 

Eventually it was time to go to bed, and unlike other kids, Kirishima didn't protest. In fact, he was pretty well behaved. But he knew he got a lot of attention and affection from his moms. 

Eijiro’s moms were great. He could tell just from this brief moment that they had raised him well. Not like he didn't know they had, but the fact that the kid was so polite and sweet as shit just cemented the fact.

He decided it was a better time than ever to show Kirishima to his own dorm. 

Kirishima had it pretty decked out with hero shit, lots of cool Crimson Riot things, and pictures on his walls. 

He carried Kirishima carefully as he dozed off on his shoulder, flicking on his light as he placed Kirishima on his bed. 

Kirishima rubbed his eyes as he sat, already droopy, and he knew this little version of his best friend was set to knock out soon.

“Hey. Wanna see my best friend’s dorm?”

Kirishima looked around, blinking up at him, and his energy came back in a flash.

“Are those Crimson Riot figures?!”

He chuckled, “Yeah, kid.” 

“Can I see them?!”

“Sure. But be careful, they're my best friend’s.”

“Is he back yet?” Kirishima asked.

“Almost.” He answered with a smile.

 

Kirishima crawled off the bed, going to the shelf where Eijiro had all his things, and he watched as he looked at everything with awe.

But then, Kirishima gasped.

“What's up?”

“You know Crimson Riot?!?”

Katsuki laughed, “No, kid. What do you mean?”

“Yes you do!” He watched as Kirishima stood on his tiptoes to pluck a picture frame off the shelf. “Look!”

Kirishima came up to him with the frame, and he was staring back at a picture of him and Eijiro. It was of them in their first year, in their school uniforms. Sero had an affinity for taking pictures after the war, and this one was taken after Eijiro had come with him to physical therapy. He could tell he was pissed off and tired, but Eijiro was smiling as ever.

“No, kid. That's my best friend.”

“Oh.” Kirishima seemed disappointed. “He has a scar like me!”

He tickled Kirishima on his stomach. “Yeah, he does. Quirk like yours, too.”

“Wow! And he's a hero?”

He nodded, “My favorite.” 

“Like I love Crimson Riot?”

He laughed, feeling his heart tug, “A little like that, yeah.”

Kirishima yawned big and loud.

“Getting sleepy, kid?”

He nodded and went back to his bed. He got settled, bringing his bear with him under the covers. He brought him to his ear and nodded.

“Riot asked if you could sleep here.”  

“Sure. But I gotta get dressed first. Okay, Riot?”

“He said okay,” Kirishima said.

He chuckled, going back to his room to change his clothes and got his futon from his closet.

He placed it on the floor, flicked off the light, and ruffled Kirishima’s hair as he lay down.

“Night, kid. Wake me up if you need anything, alright?”

“Night, Dynamighty,” Kirishima said, and he brought his bear out of the blanket.

“Night, Riot.” He said with a smile.

Katsuki took a big breath. Closing his eyes. Hopefully by the morning, his Eijiro will be back.

 

Ha. His Eijiro.

 

…Fuck. They really need to get their shit together, don't they?

 


 

The sound he knew more than his own breathing reverberated through Eijiro’s dorm, and he looked up and sure enough. There was his best friend in all his glory, snoring loud enough to wake up the whole dorm.

Damn. Thank goodness.

He hoped everyone else at the infirmary was okay now, too.

He sat up, Eijiro halfway hanging off the bed, his body taking up the whole mattress. 

“Hey. Ei. Wake up.” He nudged him lightly, flicking on the lamp Eijiro had by his bed.

His best friend didn't budge.

“Red. Wake up.” Katsuki said again, pushing him a little bit harder.

Eijiro’s snoring faltered, and he watched as he blinked awake, hair plastered to the side of his face.

Suddenly, he got up, jumped upright, and brought a hand to his chest in panic, looking around frantically. Oh shit. He didn't expect him to react like that. 

“Whoa! When the—aren't I on…what happened?!” Eijiro’s voice went up an octave, and Katsuki was quick to get up to join him on the mattress.

“Hey. You got hit with a quirk, Ei. You're alright. Actually, you feeling alright?”

Eijiro swallowed, and he realized his best friend wasn't…wearing anything underneath that blanket.

“Hold on.” He said, getting up to go to Eijiro’s drawers to toss him a pair of shorts.

“Oh,” Eijiro said, and he looked away while he changed.

 

“You feeling alright?” He asked again as he came back to the bed.

“Besides the panic? I'm okay. Um…what happened?”

“What do you remember?”

Eijiro scrunched his forehead. “I remember talking to you on comms, and then a flash of light and…now?”

He nodded, “You got hit with a quirk. You uh…you turned into a kid. You as a kid.”

“I was a kid?”

He laughed, “Yeah.”

He blushed, “Was I embarrassing? Gah, I was a crybaby as a kid.”

“You didn't cry. You were just scared sometimes.”

“Oh,” Eijiro said. “Did my moms come or something? Aizawa?”

“No. We took care of you. Denki and Mina and Hanta.”

“Really? Thanks.”

“I made you 'squid noodles'.” He teased.

“Oh god, I asked for those? It's just sausage and—”

“I know what they are, moron.” 

“Thanks for taking care of me. Sorry if I was annoying.”

“Shut the hell up. Stop talking about yourself that way, idiot.” He pushed Eijiro on his shoulder harshly.

 

Eijiro sighed, falling back on the bed. Katsuki did the same, lying down next to him. God, did he miss Eijiro. His warmth and his strength and his arms around him. He needed to fix this crap between them. 

“Hey. I'm sorry about…I'm sorry that we fought about stupid shit before this.” But wait, it wasn't- “Not stupid shit. I mean. I'm sorry I was being stupid.”

Eijiro shook his head. “I get where you were coming from. It wasn't fair for me to give you an ultimatum.”

“No. It wasn't.” He agreed.

He invited Eijiro into his arms, and his best friend relaxed with his touch.

“I do love you, Eijiro.” He admitted.

“Then why did you…” Eijiro asked, wrapping an arm around his waist. 

“Because I'm stupid.”

He was stupid. Eijiro had asked if he had feelings for him. If he wanted to move in together after graduation. 

When Katsuki had hesitated, had said no…Eijiro had said that he couldn't see them being friends anymore if they weren't together. Accused him of being too closed off. Scared. It fucking hurt to hear. 

 

“I don't want you to agree to live with me if…I don't want you to agree to being with me if you don't want to. Just because you feel bad.”

“I don't feel bad.” He scoffed.

Eijiro got closer, leg hitching over his hip. He nuzzled his nose into his neck and sighed. 

“I shouldn't have said we wouldn't be friends anymore. And everything else I said. I'm scared too.” 

“No. You shouldn't have. You fucking hurt me, asshole.” He clicked his teeth.

“But that's not the only reason you…”

“No. No, Eijiro. I just needed some time, alright? I do want to be with you.” He confessed.

“Yeah? You mean it?” 

“Of course I mean it.”

Eijiro brought their faces close and pressed their lips together lightly.

“I'm sorry,” Eijiro said again.

“I'm sorry, too,” Katsuki said back.

“I love you. A lot, Katsuki.” 

“I love you, too,” Katsuki said.

He kissed Eijiro lightly again. 

“So you wanna do it? Be together and move in after graduation?”

“Yeah. I do.”

“Okay,” Eijiro said. 

And just like that. Everything was right in the world again.

Damn. Katsuki had a whiplash of a couple of days. He needed to fucking rest.

“Still sleepy? Wanna sleep some more and eat a late breakfast?”

“Sure, Eiji.” He said. 

“Love you,” Eijiro said back.

Katsuki kissed Eijiro again in lieu of an answer. But he felt that it was answer enough. 

Because he did love Eijiro. He'd take care of him in any shape or form. In every lifetime. He couldn't believe he almost robbed himself of that.

But that's a thing he didn't need to think about anymore. He had Eijiro. His Eijiro. And that's all that mattered. 

 


 

“Kiri! You're back!” Kaminari shouted, running out of the common room kitchen with a spatula in hand.

“Hey, Denks!” Eijiro chuckled. Denki hugged him tight.  

“Man, you were such a cutie as a kid, but I missed you, dude!”

“I hope I wasn't too much.” Eijiro blushed. 

“You don't remember anything?” 

Eijiro shook his head, “Nope.”

“Aw, well, we had a good time! Played video games and stuff.”

“Thanks for taking care of me, Denks.”

“Of course! We kinda had to force grumpy over here, or he would've done it all himself.”

“Shut up.” He groaned. “Come on, Ei. Let's go get breakfast.”

“Wait, hey! You don't wanna come join me and Hanta? I was gonna make pancakes. Got a bunch of fruit and stuff at the store.”

“Yeah sure! I'd love some!” Eijiro beamed, and he let himself be led into the common room.

“You better not make them shitty.” He complained.

“Wow, Blasty. I love your words of encouragement!”

Sero laughed, “He watched like ten million videos. I think we’ll be okay.”

Either way, Katsuki was gonna keep a watchful eye.

 

He sat on the counter next to Eijiro, his stomach jumping when he kissed him on the cheek. 

Kaminari came back to the counter with a smile, giving them both a mug of tea.

“Enjoy!” 

“Thanks, Denks! Wow! Five-star treatment, huh?”

“Only the best for my best friends,” Kaminari said with a stupid bow. 

Katsuki took a sip out of his mug, surprisingly perfect, and let his head rest on Eijiro’s shoulder. 

Eijiro let out a small laugh, kissing the top of his head.

Katsuki couldn't help but smile either. If this was a glimpse into the rest of their lives? Taking care of each other? Being with their stupid friends? 

He can't wait for the rest of it. And who knows, maybe a kid to take care of in the future. 

 

Notes:

I've been wanting to try my hand at a quirk accident fic like this!! hope you enjoyed all the cuteness <3