Chapter Text
It was their third year in UA, where Katsuki and Izuku had once again moved into the Heights Alliance for their final year before they graduated and became fully fledged pro heroes. They were only a couple of months into the new school year, the weather warming up from the spring chill.
It was a pretty routine schedule of classes and internships that greeted the third years. A routine that Izuku was used to and today was Sunday, which meant it was the one day that Izuku would allow herself to sleep in.
That is until she woke up to a tiny something slapping her face and unfamiliar childish gurgling.
It was a baby Kacchan that was blinking wide red eyes as he gurgled noisily, sitting in the comically oversized shirt - that literally covered nothing, a shirt that Izuku knew her boyfriend had been wearing last night before they went to bed at god knows o’clock in the morning.
“Ka-Kacchan?” Izuku wondered as she blinked green eyes at her not-boyfriend. What on earth?
The baby, seeing that the big girl was awake, began to clumsily clap his hands in excitement.
Izuku slowly sat up and pinched herself hard. Ouch, not a dream then. But her boyfriend was nowhere to be found and a baby that looked exactly like his baby pictures that Aunt Mitsuki had sneaked her, was sitting next to her in Kacchan’s dorm room. Her boyfriend nowhere in sight.
Was this a joke? An elaborate plan? Izuku shook her head, Kacchan wasn’t the type of guy who even appreciated pranks. He wouldn’t shock her with something like this. Izuku poked the stomach of the baby in front of her and gasped at the soft, so very soft skin of the child in front of her.
The baby, maybe more than a year old, started to frown and pout his - frankly adorable lower lip. Big ruby eyes glistening with unshed tears. Oh no. That was the only warning Izuku got before she was staring at the red face of an upset toddler with a set of lungs to rival Present Mic.
The shrill cries of the baby had Izuku flustered and she immediately scooped her boyfriend(?) into her arms in an attempt to shush the poor thing. She noticed how cold baby Kacchan’s skin was and frowned before taking the discarded shirt and wrapping the baby as best as she could. The shrill cries tapered off to a semi-decent level of wet sobs and Izuku sighed in relief, rocking the child in her arms in an attempt to soothe him.
“B-Bakubro?” a hesitant knock on the door and the familiar voice of Kirishima.
“K-Kirishima-kun, c-come in” Izuku called out nervously, bringing baby Kacchan to rest along her torso so that the baby could rest his head on Izuku’s shoulder. The door opened and Kirishima’s messy red hair poked in warily before bright red eyes widened in disbelief at the sight before him.
“Y-Yo, Midoriya… Is that... “ Izuku only blushed fiercely.
“H-he...K-Kacchan!” she could only stutter helplessly as the baby started to fuss once again in her arms.
“I didn’t even know you were pregnant!” Kirishima chokes, hand to his heart in disbelief. He didn’t think Bakubro was so irresponsible to not use protection. He wasn’t ready to be an uncle goddamnit!
“What!” was the loud yell of disbelief that startles the baby in her arms and the sobbing returned with waterworks. Oops, he might have said that last bit out loud and shocked Midoriya who looked as frazzled as she sounded.
Izuku immediately turned her attention to the wailing baby in her arms as he clenched tiny fists in her sleep shirt.
“Oh no, please don’t cry Kacchan.” Izuku cooed as she rubbed a gentle hand in circles on Kacchan’s back. Kirishima gasps at the use of Midoriya’s childhood nickname for his best friend.
“Wha- Is that? It can’t be. Are you-” Kirishima stutters as he walks towards Bakugou’s bed. “That can’t be Bakugou.” He almost whimpers in disbelief, Izuku rolls her eyes.
The baby reached a tiny hand out and tugged on her hair and blinked big red eyes when Izuku winced at the sharp tug. Repeating it a couple of times and smiling when the big girl would make the funny face.
“Holy shit, he’s enjoying your pain. That’s definitely Bakubro.” Kirishima breathes as he sat heavily on the ground. Izuku sends a glare towards Kirishima for cursing in front of her baby-fied boyfriend. The sound attracting Kacchan’s attention and he unintentionally pulled on Izuku’s hair even harder as he turned to face the redhead.
“Alright Kacchan, it’s time to let go of my hair.” Izuku gently pried baby fingers off her already tangled locks. The baby gave one last (surprisingly strong) tug before letting go, and Izuku sighed in relief. Settling the baby on her lap, Kacchan finally took the chance to observe his unfamiliar surroundings.
“Does he even understand us?” Kirishima asked as he slid his butt across the floor and rested his chin on Bakugou’s mattress.
“I mean, he’s a baby.” Izuku could only shrug.
“What even, Midoriya?” Kirishima curiously stares at the baby that was distracted by the way Midoriya’s fingers curled around his stomach.
“We got home late from our patrol with Gang Orca, cause you know how far his office is from campus. Kacchan was being a grump as usual, he was missing his bedtime you see, you know how he likes to be in bed by 10 and it was already 1 in the morning. I didn’t even notice anything was wrong with him? We had different patrol routes and he didn’t tell me if anything interesting happened. And he asked me to, you know, sleepover -cause apparently I’m the one who missed cuddling-”
“Oh my god, Midoriya, TMI.” Kirishima waves a hand interrupting his best friend’s girlfriend’s verbal diarrhea.
“S-sorry.” Izuku meekly tries to hide her blushing face with one hand as the other hand continued to hold on to the squirming baby in her lap. “A-anyway, I woke up to something hitting me and I open my eyes to see a baby version of my boyfriend.”
“Oh man… We-we gotta call Aizawa-sensei.” Kirishima slowly lifts up a hand in front of baby Bakubro, catching the attention of a pair of ruby red eyes, the baby grabbed the offending finger in his tiny fist. “Oh my god, he’s so cute!” Kirishima grins toothily at the baby. The wide smile seemed to scare him though, and Katsuki ended up flailing his arms as he screamed to get away, hitting Kirishima in the eye with his own hand. The redhead hissed in pain but the giggle coming from his best friend, uh- best baby? was totally worth it.
Izuku gave Kirishima a sympathetic smile before she lifted baby Kacchan into her arms once again and tried to soothe the little scream machine. Nudging Kirishima with her foot, she got off the bed when the redhead made some space, keeping his arms out to catch her in case she lost her balance. She had her arms full with a wailing baby after all. A wailing baby hell-bent on kicking out one of her ribs it seemed.
“You call Aizawa sensei and tell him to give Recovery Girl a heads up. I’ll see if Momo is up and if she can make him some diapers.” Both of them winced at the thought of baby bakugou soiling himself and cleaning up after him.
“Right!” Kirishima scrambles to get up and quickly leaves Katsuki’s dorm room to his own. Probably to get his phone. Izuku stood in the middle of the room, dressed in only her pajamas from the night before and sighed. Adjusting her hold on Kacchan so that he rested on her hip, she unlocked her phone and began to scroll through her contacts.
“Momo-chan? I need a favor.”
===
It had only been thirty minutes where Izuku sat in the dorm’s living room with a baby Kacchan in her arms, apparently, the blonde didn’t like being surrounded by too many people and had started screaming when some of their classmates started to crowd around him and Izuku.
Right now, only Izuku was seated on the three-person sofa and Kacchan would start tearing up if anybody got even a little too close to the furniture he had seemingly claimed for himself.
Iida, Tsuyu, Kirishima, Momo and surprisingly enough Tokoyami seated on the opposite sofa a considerable distance away, not wanting to trigger the waterworks.
Momo was a life saver and had only blinked at the sight of Izuku at her door with a baby on her hip. Clearly not expecting to see one of her close friends holding a baby version of their boyfriend. It certainly wasn’t the strangest thing to open her door to. Kaminari-kun had won that honor when he had knocked on her door at 5am in the morning with a broken microwave in his hands. She didn’t want to know.
Baby Bakugou now wore a set of diapers and a cute short-sleeved red onesie with little bombs. The girls had laughed at the image of the baby, who refused to be separated from Izuku or face his wrath. Momo had even been kind enough to make a couple of diapers for Izuku who could only sigh in both relief and trepidation.
Aizawa sensei stood a good distance away, babies weren’t his forte. He couldn’t handle any child younger than the age of ten. Gang Orca was on the phone, telling him what had happened during last night’s patrol.
Recovery Girl had just arrived and the few members of Class 3A parted for the Youthful Hero. Kacchan had been hungry and was now being fed soft pieces of bananas by Izuku who dutifully broke off pieces of the fruit for her young charge.
“Well, can’t say that this is the first time this has happened in UA.” Recovery Girl hums as she got closer to the young Bakugou boy. He looked ready to cry before Izuku gently nudged his mouth with more banana.
“According to Gang Orca, he and Bakugou had come into contact with a petty thief who could rewind time of the things he touched. It's obvious why he was successful in robbing nearly fifteen stores in the past 3 months.” Aizawa offered as he hung up and made his way to the group. “The effects of the quirk weren’t immediate, and the amount of time that's reversed depends on how long skin to skin contact was established.”
“They had a pretty long brawl before Gang Orca could break them up. Unfortunately, the villain got away and escaped arrest.” He finished with a sigh, the atmosphere in the room was tense. Iida looked like he wanted to say something but was interrupted by a squeal. Everyone turned to the elevators to see a bright-eyed Ochaco hurrying over.
“Deku-kun!” her voice was practically shrill at the sight of the baby in her best friend’s lap.
“Am I an Auntie now?!” She cried out and Tsuyu was about to warn her, but it was too late. The moment she got to close, Bakugou started wailing and throwing his fists, knocking the banana from Izuku’s hands.
“Oh Kacchan, it’s alright, it’s only Ochaco-chan.” Izuku soothed as she stood and positioned the baby in her arms to press his head against her shoulder. “She’s not scary at all.” While Izuku attempted to soothe and rock the young child, Chiyo took out a tablet and began entering some data. She gently pried open Bakugou’s mouth and noted that the baby had all of his front teeth. Roughly gauging his height and weight, asking Midoriya about how she had found the baby.
“I’ll need to take some blood samples from the boy and run some tests.” Recovery Girl says as she rummages through her bag.
“Oh, Kacchan is definitely not gonna like that.” Izuku murmured worriedly.
“Sit him on your lap and hold him still, Midoriya-chan.” Recovery Girl pats the sofa, Tsuyu quickly clearing the discarded banana and IIda standing as close as he dared in support. It was Dark Shadow that had finally managed to catch baby Bakugou’s attention and the screaming finally stopped.
“Look at the pretty birdie, Kacchan.” Izuku cooed as she firmly holds one arm down. Tokoyami reluctantly seated next to her as Dark Shadow -who preened at being called pretty, tried to play peek-a-boo with the baby. Bakugou’s free hand trying to reach for the bird-like thing in front of him.
Thankfully Recovery Girl managed to draw blood as quickly as possible, obviously used to dealing with fussing children, and had a bandaid on Bakugou’s arm before the baby could even start tearing up from the sharp pain. The blood quickly and securely kept into her bag before she began rummaging for something else.
Bakugou looked down at the colourful bandaid on his arm, not registering the pain until it was too late and confused tears begin to pool in his big eyes. Izuku immediately began to let out soothing noises in an attempt to dissuade the wailing.
“Man, I didn’t think he’d be such a crybaby.” Kirishima mock-whispered to Uraraka before Momo elbowed him hard in the ribs. “He is a baby.” She hissed.
“Midoriya-kun! What are you going to do now?” Iida asks, his hands chopping in the air. For some reason, this attracted Bakugou’s attention and distracted him enough to stop crying before it even started.
“I-I don’t know how to take care of a baby…” Izuku mumbles as she gently and carefully positions Kacchan so that he faces both Tenya and Dark Shadow. Both of them immediately set to work in distracting the child.
“So I guess, we can call him Babygou now?” Kirishima wonders out loud and this time it was Iida who smacks him.
“Here give him this gummy and it’ll take the ache away.” Recovery Girl holds her hand out for Izuku. “It’ll be like the pain never happened.” Izuku obediently opens her hand and a couple of gummy bears drops onto her palm. “He’ll only need one, or he’ll be too energetic.” The hero warns.
“Gang Orca is sending all details on the perp to me, hopefully there’s something about changing him back.” Aizawa stares pointedly at the distracted baby. Izuku stiffens, oh she didn’t like where this was going. “Until we get more information, Midoriya, you’ll be in charge of taking care of... Babygou.” Kirishima fist pumps at the use of the nickname.
“B-But we don’t have anything in the dorms to take care of a baby!” Izuku attempts to protest. “Can’t any of the teachers or-or even Recovery Girl take care of him?” Izuku turns pleading eyes to the nurse who only shakes her head.
“I’m sorry, but we don’t actually have anyone who’s qualified to do any DNA analysis in school, so I will be leaving to hand this over to the lab.” She says as she begins to pack her bags. “I’ll be leaving now.” Once again the students parted for the Youthful Hero.
“The teachers hardly have baby ready rooms, Problem Child.” Aizawa frowns. Izuku visibly deflates and Bakugou must have sensed the change in the mood because he turns his big red eyes to her and attempts to smack her face with his pudgy hands.
“Oh Kacchan, I’m not sad.” Izuku smiles as she cuddled the baby in her arms.
“He’s so cute!” Ochaco squeals excitedly as she holds onto Tsuyu’s hands. Momo could only agree as she takes her phone out to take a photo of the moment.
“Aww, don’t worry about it Midoriya, I’ll help you take care of Babygou.” Kirishima grins excitedly as he bounces on the balls of his feet.
“We will all help out our classmate in his time of need!” Tenya declares, arms pumping into the air. Cheers and agreements echo around them and Babygou only startles at the sudden loud sounds. He buries his face into Izuku’s neck and smacks her painlessly on the chest.
“You guys, you’re too loud!” Izuku attempts to scowl as she once again attempts to soothe her blond charge, but the bright smile on her face betrays her relief. Yeah, they could take care of Kacchan. It shouldn’t be too hard.
==
Soon enough, the news of Babygou spread to the rest of the class, courtesy of Momo sharing the photos in the class group chat. Izuku spent the morning with her classmates, figuring out what they would need to take care of a baby. They didn’t even know how long Bakugou would stay as a child.
Aizawa had left the teens to their own devices, with a warning to not corrupt the baby.
“If you need to buy anything for Babygou off campus, get me or one of the other teachers to escort you. We can’t have any more babies running around in UA. Until the villain is detained, nobody is allowed to leave school grounds without an escort.” The glow of red from their teacher’s eyes had everyone agreeing almost too easily.
Nobody wanted to be reverted back to babyhood, thank you very much.