Chapter Text
Katsuki recalled the day he first presented like it was yesterday.
He had been fifteen at the time, and in his first year at UA High; training to become the future number one hero in Japan.
He had set that goal for himself the minute his quirk first presented back in his early days of elementary school. He let the praises of his peers and teachers alike get to his head and since then he has had his eyes set on that goal and nothing else.
There was no doubt that he was a gifted child.
However, as of late, he hadn't felt as gifted. Especially since his stomach decided to start cramping during one of their training sessions on Ground Beta. He tried to ignore the stabbing feeling in his lower abdomen, as well as the pain in his muscles. He could endure it. Atleast, that’s what he had told himself.
It proved to be even more of a challenge as their session had finally come to an end and he could no longer stop himself from doubling over in pain when an especially sharp cramp stabbed right through him. His friend, Kirishima, had noticed his curled up state on the floor and immediately ran to his aid.
“Bakugo! You alright, Man? I didn't go too hard on you, did I?” He bent down in front of the blond, tone laced with concern.
“I-I’m fine, Shitty Hair. Just must've over-done it yesterday with extra training.” He tried to brush off, steadily getting back to his feet. Kirishima had tried to help him up but his hands were quickly swatted away.
“That was some serious tra- woah. You good, Kacchan?” Kaminari approached the two, with an uneasy look upon his face.
“F-fuck off, Sparky!” The blond hissed out, massaging his cramping abdomen. “Why's everyone all up in my business, huh?” He tsked, standing on unsteady feet.
“We’re just worried ‘bout you, Bro. No need to be so aggressive.” The yellow-blond apologized, watching the other boy make his way towards the changing rooms with a slight wince with each step.
The other two shrugged their shoulders then followed the blond in order to get dressed back into their uniforms.
Katsuki scowled at the two, as they fell into step beside him. All he needed was a nice warm shower to soothe his aching muscles, then he’d be back to normal.
Or, that's what he had originally thought.
The pain continued to worsen as he tried to resist the urge to instead crawl his way to the bathroom. Every movement felt like he was being stabbed in the abdomen a thousand times with knives.
He swallowed a whine, and quickly got undressed, moving into the shower cubicle. He switched on the water, making sure it wasn't too hot as to not let his body explode, yet warm enough to soothe the aches and pains away.
As he was about to clean around his crotch area he almost had to double take at the sight of blood dripping down his inner thighs, below his dick.
What the fuck? He thought to himself, stepping under the water once more. It got rid of the blood for only a second or so, before it came flowing back.
shit.
He didn't know how on Earth he was supposed to get out of the shower and to his locker without the other guys seeing. It may just be a minor cut that he got down there somehow, but still, the placement was rather embarrassing.
Mustering up enough courage, he decided to grab his towel off the door handle and wrap it around his waist. He was usually more than okay with walking around the locker room butt naked, like everyone else, but today there was no way in hell he would do such a thing.
With a deep breath, he opened the cubicle door and walked out into the changing room, heading straight for his locker. He was suddenly blocked by Sero who was fully dressed in his school uniform once again.
“Hey, Dude. The squad and I were wondering if you were up for some chill time in Ashido's dorm this evening? Just the usual game play, snacks and whatnot.” He asked, a slight hint of desperation could be seen in Kirishima's face as he walked by, alongside Kaminari.
He would never admit it, but he secretly liked hanging out with those four idiots. Maybe it was because he grew up as an only child and craved that type of contact with others. That suppressed urge to be held and loved. His parents had failed in that department. Along with many other things.
Brought out of his thoughts, he was about to respond to the taller boy when he suddenly felt a light tap on his shoulder from behind. He turned around and was met with the lifeless stare of heterochromic eyes that belonged to Shoto Todoroki.
Katsuki never really paid the boy any mind. He was often seen by himself or hanging out with Deku and his own band of friends. He seemed rather socially awkward which made sense regarding his background.
“Whad’ya want?” He huffed at the boy, running out of patience.
“You're-” Todoroki composed himself before he spoke again. “you're bleeding… down there.” He informed him in his regular monotone voice. Katsuki silently cursed to himself as he looked down to see that same blood running down his legs, and causing a mess on the bathroom tiles.
His cheeks flushed bright red in embarrassment, as all the other boys in the room turned around to stare at him, whispering amongst themselves. Todoroki, the bastard he was, simply shrugged and walked away.
“Shit, Bakugo, that looks really bad. Does this have to do with the pain you were in earlier?” Kirishima made his way over. He could tell that the blond wanted to yell at the others to get a move on, but was in a state of shock.
The blond didn't respond. The redhead took matters into his own hands and told the others to walk back to class in the meantime. He had to help his friend.
“Come. Let's get you to Recovery girl's infirmary. She can help you-”
“No!” Katsuki seethed, baring his teeth suddenly. Kirishima wasn't sure if he was seeing things but it looked as if his blond friend had a new pair of sharp little fangs in his mouth. “I don't need that old hag's help.” He practically growled in defense.
“Don't be so stubborn. You're in a lot of pain right now. Get dressed and we can go visit her straight away.”
Without another word, the blond grabbed his uniform from his locker and clumsily made his way back into the shower cubicle to get dressed in private.
Once he was done and had cleaned up his legs and inner thighs, he unravelled a heap of toilet paper from the roll and shoved it into his underwear, hopefully catching the blood flow.
He then got dressed and joined Kirishima, walking beside him to the old woman’s office. Surely this was something more than just a cut. The blood seemed thicker and darker in a way, much to his disgust and dismay.
Once they made it to the infirmary, Kirishima knocked on the door with a steady hand, then retreated backwards.
“I still think this is stupid.” The blond pouted, shoving his hands into his pockets with disinterest.
“Trust me, Man. It's better than going through the rest of the school day like this.” He chided.
Suddenly, the door opened to reveal the smaller woman who smiled up at them. “What can I do for you boys today?” She asked in a kind voice.
“Bakugo over here’s been in pain the whole day and started bleeding /down there/.” Kirishima announced, much too loudly for the blond's liking, so he sent a glare his way.
“Oh dear. Come inside.” She opened the door wider to let them both in.
She then instructed Katsuki to take a seat on the medical bed as she got out her clipboard and pen.
“So. Tell me what you've been experiencing, Young Bakugo.” She took a seat in her chair holding up her pen, ready to jot information down.
“Well, I have been experiencing cramps basically throughout the week, but it's been especially bad today. My muscles are also very sore.” He admitted, avoiding eye contact.
The nurse hummed and jotted down a few things.
“Anything else?” He pondered for a moment.
“I, uhm… also started bleeding down there like Kirishima said. I discovered that when I was in the shower earlier.” He tried to swallow a sizable lump in his throat, feeling his cheeks flush. “Oh, and I suppose my neck’s also been really itchy, but I don't think that's related.” He shrugged, watching the nurse's expression change from one of thought to sympathy.
“Young Kirishima. I think it's best if you head to class now. I need to speak to your friend here in private, if you don't mind.” She suggested politely.
“Oh, not at all, Ma'am!” Kirishima waved, walking back towards the door. He looked back at his friend one more time with an unsteady smile. “I'll see ya later, Bakugou. Hope you find out what's wrong.” He then left, shutting the door behind him gently.
“Now, answer this question honestly, Dear. Have you presented yet?” She asked him, bringing his mind back down to Earth.
“Huh? Oh, no.” He replied, making her hum in acknowledgement. She wrote down a few more things.
She then turned to open a cabinet and took out a box that looked foreign to the blond.
“Here, take three pads for now. They'll catch the bleeding. It's normal for there to be a lot on your first period. There's also instructions on the box that you can follow.”
“I- uh, what?” He stammered, taking the items into his hands. He awkwardly stared down at them with perplexed emotions before he was guided to the infirmary bathroom to put one on.
With some difficulty, he managed to finally apply the pad in his underwear as best as he could. It felt a bit uncomfortable as he was wearing boxers and his dick was in an awkward position. He then walked out.
“Lay down for me. I’ll explain everything in a minute.” She instructed, hopping off her chair to go and fetch her equipment.
Katsuki did as told and climbed onto the bed, laying down, unsure of what to make of all this. Judging by the nurse's expression, this was something serious
She soon returned, wheeling in an odd looking machine. “What's that?” He cocked his head to the side, looking at it with uncertainty.
“It's an ultrasound machine. I just need to check something.” He had heard of those machines before. They were used to check up on pups still in the womb or if there were any other issues happening inside there.
What did confuse him, however, was the fact that he himself didn't have a womb, right? He wasn’t a girl. But then again, she mentioned something about his period? So what was this old hag-
“Lift your shirt please, Young Bakugo.” He obliged and lifted up the hem with shaky hands.
She then warned him that this step may feel a bit odd, as she squeezed cold gel onto his lower abdomen and moved around a wand.
She looked up at the screen as an unreadable expression overcame her features.
“So? What's wrong with me?” He asked, getting annoyed with all of this.
“You see that?” She pointed to the screen. He sharply looked up at the screen with a cock of his head. “What about it?”
“You have a womb now. In other words, your body is currently presenting itself as an omega.” She supplied. “That’s why you have gotten your period and are bleeding so much. You're currently in the first stage of transitioning into an omega. Also makes sense as to why your neck’s been itchy. You're busy developing scent glands.”
The blond froze in place, as panic became evident in his eyes. He couldn't be an omega. He just couldn't. His parents hated omegas with a burning passion, he'd get kicked out!
“Don't worry, Dear. I know it's a lot to process, but you'll be alright. Rather tell your parents now so that they can get you all the supplies you need for your first heat.” She tried to comfort him, not knowing the fact that that was the last thing he wanted to do.
“I'll give you some heat suppressants, as well as some pills to soothe the pain, but I'd advise that you don't take the suppressants on your first heat. Rather let it all play out naturally once it arrives.”
With another look of pity thrown his way, he was handed a sweet to calm his nerves down. He gingerly took it and popped it in his mouth whilst she wiped his stomach clean. She then handed him a packet of what looked to be scent patches, as well as two bottles of supplements.
“Now, allow your neck some time to form your scent glands before you apply a patch. I'd say it'd take about three days until your scent properly kicks in, but it will be obvious once the glands are formed. It is a slightly uncomfortable transition.” She smiled sadly at him.
He stared down angrily at the supplies in his hands and muttered a thanks, as he headed for the door.
“Oh, and Young Bakugo, I will have to inform the school of your new secondary gender, as it is protocol. And like I said before, it's best that you tell your parents now rather than later.” She told him sternly, “Do take care, Deary. Not that I don't believe in your capabilities, but omegas are quite targeted, especially male ones for their smaller numbers.”
He frowned, then turned the door handle, walking out. He took a deep breath in, then out, and made his way towards class, shuffling awkwardly with the foreign item in his underwear.
An omega, huh? What a joke.
No one ever took omegas seriously, especially his parents. They hadn't even bothered to educate him on what happens to the body during omega-presentations. And now the staff would know.
He just hoped they'd keep this newfound information to themselves.
Once he arrived at his homeroom classroom, he muttered an apology to his teacher then slumped down into his desk chair.
“Psst.” He heard someone whisper. He looked around the classroom until his eyes landed on Kirishima. The boy mouthed out the words ‘Are you okay?’ as Katsuki rolled his eyes and nodded, turning his attention back towards the front of the class.
-
The school day was finally over. Katsuki made his way back up towards his dorm room, shifting awkwardly with the sound of his underwear ‘crunching’ and pain that still laced his body.
He should probably take those damn pills soon.
He slammed his dorm door shut once he was inside and slid to the ground, curling up in a ball.
Fuck.
He felt like crying, but that was for weaklings, so instead he held his tears back and grabbed the pills for his cramps, dry swallowing them then grabbed his book from his bedside table, trying to distract his mind.
He quickly got bored of his book, so instead he decided to pull himself up off the ground and do some research on presenting as a male omega.
He flipped open his laptop, getting comfortable on his bed whilst he opened a new tab and quickly found a website. He read that he should change his pad once every three hours or so, besides night time where he'd have to wear a thicker one to prevent leakage whilst asleep. He groaned at the fact that he may have to go back and ask for those for tonight.
What the old lady had also failed to mention was, much to his dismay, that his dick would continue to shrink throughout the first two weeks of presenting, and in place he'd only have… a vagina.
A whine slipped past his lips as he continued to read all about omegas.
Were there even any upsides to being an omega? He wondered.
Suddenly, a knock at his door caught him off guard as he slammed his laptop shut and shoved it under his pillow.
“Who is it?” He shouted.
“It’s Kirishima. Are you still gonna join the squad’s hangout at Mina’s tonight? I understand if you're still feeling poorly though.” Kirishima's muffled voice sounded from behind the door. Katsuki cursed under his breath, only staring into his lap, unblinking.
“Not tonight… sorry, Shitty Hair.” He mumbled.
“Oh. Uh, that's alright. Hope you feel better tomorrow, Man. I’ll win Mario Kart for you.” The redhead’s footsteps grew softer the further he walked away until he could no longer be heard.
The blond let out another sigh, turning to face the wall on his side. He'd get through this. Even though he never asked to be an omega, he'd own it. He'd show these people who will still be the next number one hero. Katsuki Bakugo didn't give up that easily.
His second gender would not stop him from achieving his life’s goal… He was so sure of it.
–
The week was over before the blond even knew it. The blood flow had lessened over the days and he now found himself having to deal with his newly formed scent glands. He looked at himself in his bathroom mirror after a week of avoidance, and applied scent patches to his neck and wrists.
It'd be hard to hide them from his parents once he went back home for the weekend, seeing as it was still summer, so sweaters or scarfs were out of the question. But if he didn't wear the patches then he'd be at risk of his scent leaking out.
His mind continued to go back and forth, as he moved away from the mirror and collapsed onto his desk chair in defeat. He gathered his homework and began to scribble down the answers to a question on autopilot.
He supposed he could just take scent suppressants, but he had read a lot of negative experiences with taking those relating to long term scent and hormonal damage. Still, he wouldn't take them everyday, and he supposed it'd be better than his parents finding out. During the week, thankfully, none of the teachers had addressed his new secondary gender. Although, he could tell his homeroom teacher, Aizawa, wanted to say something to him.
Once he had finished his homework, he shoved his books back into his school bag and flopped onto his bed. He didn't know if it was his newfound hormones, or another unknown reason, but something about his bed felt wrong.
He tried rearranging pillows but it still felt off. With great defeat, he got up and threw open his dorm door. He stomped his way downstairs to go and start dinner for the class.
They had assigned him to that task the minute they found out he was one of the only class members who knew how to properly cook, and a small part of him didn't mind that so much.
Rather, he felt quite chuffed to put his skills to good use and provide for his class of idiots.
As he entered the kitchen, he was greeted by Kirishima who had his hair tied back with a white bandana, drinking what looked to be one of his disgusting protein shakes.
“Oh, hey, Man! What’s up?” He waved him over.
“I was just about to start on dinner.” He huffed, reaching for a pot.
“Yum! I can help-”
“Last time you tried to help in the kitchen you almost burned the damn building down.” The blond tutted, making the redhead pout with a nod.
And so, the redhead watched his friend work meticulously around the kitchen, as if he had everything mapped out already. He supposed they had been living in the dorms for a while now.
Once dinner was served, everyone came downstairs and sat at the dining table, talking about their day. Katsuki chewed on his food in silence until Iida suddenly cleared his throat.
“Bakugo, I couldn't help but notice those patches on your neck and wrist. Any reason for that?” The rest of the class all turned their gaze towards his neck, as he tried not to shiver at the sea of eyes upon him. He self consciously placed a hand on his neck, covering the patch.
“None of your damn business, Four Eyes.” He snarled, lip curling up.
And there they were again. The same little fangs that Eijirou had noticed a week ago. They were admittedly more cute than threatening. It reminded him of a cat or fruit bat.
“They seem to be scent patches if I'm not mistaken.” Sato suddenly spoke up. “I know this because my sister presented recently.” The large brunette then went back to eating as the class spared one more look at his patches.
“Does that mean you already presented, Bakugo?!” Ashido gasped, as the others muttered amongst themselves.
“It would make sense since you’re the oldest.” Uraraka chimed in.
“Shuddup!” Katsuki snapped, hating the attention that was on him.
“I can't wait to see what I present as!” Another voice piped up. The blond just sank further and further into his chair. Todoroki and Kirishima remained silent throughout the whole ordeal. He sent a knowing look across the table to his redheaded best friend before he got up and left. He headed for the front doors that lead to the garden, desperate need of some fresh air. He picked up speed as he rounded the corner. The dining room had felt far too stuffy back there. He caught his breath and quietly opened the doors, creeping out. He took in a deep breath once he felt the cool night air kiss his exposed skin. He didn't understand why the topic of secondary genders bothered him so much, but it did. He moved away from the Height's alliance walls and walked towards the front garden, basking in the moon's gleaming light. For the first time in a long time, he properly felt alone with his thoughts and himself.
Now outside, he peeled back his scent patch to catch a whiff of his own scent;
Caramel campfire…
He jumped at the sound of the door suddenly opening behind him, and turned around to see who it was.
Todoroki closed the door behind him before he walked over to the blond.
“I noticed you were uncomfortable in there. Are you alright?” He asked, quietly. The two toned boy was so sure he and the blond were friends, or at least on even footing, despite the blond's constant denial.
“Tch, what's it to you?” He frowned, turning his back to him once more and folding his arms across his chest.
“Your second gender… you presented right?” He asked, making the blond raise a brow.
“Yeah, so?” The taller boy moved to stand in front of the blond.
“You're an omega.” The blond froze.
How the hell did this bastard know? “You're probably wondering how I know… well, you were, erm, bleeding at the beginning of the week in the changing room. That was your first period, wasn't it? Only omegas get periods, well, besides beta women.” He explained.
“What? You some kind of secondary gender expert or somethin’?” Katsuki snapped, feeling on edge for some reason.
“No. I just know.” He trailed off.
“You should come back inside. It's cold tonight.” The taller boy explained, even though Katsuki begged to differ. He needed that minute of peace outside. It was a stark contrast to his loud home life and the bustling dormitory building.
With a roll of his eyes, he followed Todoroki inside and back towards the kitchen to help clean up.
Kirishima noticed his friend's presence and bounded over to him like a worried puppy.
“Are you doing alright, Bro?” He asked the blond, eyes zoning in on the pointed out scent patches.
“Yeah. Just needed some air.” He sighed, grabbing bowls from the dining table to stack in the dishwasher.
Once they finished cleaning up, the redhead followed his friend up the stairs towards their dorm rooms. Kirishima was about to walk into his own room until he noticed the look on his friend’s face. He didn't need a vocal invitation to know that the blond wanted some company. Kirishima nodded and abandoned his door handle, walking into Katsuki’s room right behind him. He took note of the rather messy bed, and a pill bottle sitting on his bedside table.
“What's up, Man?” He asked, taking a seat on the blond's desk chair, getting comfortable. Katsuki himself took a seat on the edge of his bed, as his gaze tried to look anywhere but the redhead.
“So, uh, you know when you took me to see the ol- Recovery girl on Monday?” He asked.
“Yeah? oh no, please don't tell me you're dying…”
“What? No, you idiot! I was just presenting. That's why I was in so much pain.” He blurted out.
The redhead blinked once, then twice.
“Oh? Ohh, everything makes so much sense now.” Kirishima's eyes zoned in on the scent patches that sat on the crook of the blond's neck, then shifted to the unopened bottle of pills.
“And the blood?”
“Y-yeah, that was also part of it.” He bit his lip. “I’m… an omega...” The other boy's eyes widened as he sat in shock. That was the last gender he'd expected his hotheaded friend to present as, if he was being honest with himself.
“Wow.”
“I know. I'm a joke.” The blond let out a wet laugh. Suddenly, before he could even register, he was engulfed in a warm and stable hug.
“You'll always be my friend, Bakugo. No matter what comes between us and no matter what you are.” He squeezed harder. Katsuki let himself go in that moment and embraced the hug, moving his hands to wrap around his friend's bulkier frame. He needed this. He couldn't recall the last time he had been hugged by someone.
That night, Katsuki lay in the arms of his redheaded friend. The calm before the storm as one would say. His parents were fetching him tomorrow, as every Saturday the students would go home for the weekend and then be dropped off Monday morning.
His smile faltered a little, as his mother came to mind. He turned to the bottle of scent suppressants on his bedside table. If his mother asked about the redness around his neck and wrists he'd simply say that they were mosquito bites.
Nothing more than that.
Finally, he let his eyes flutter closed as sleep was welcomed over his body.
-
The following morning, Katsuki sluggishly dragged himself out of bed. He looked around but there was no sign of Kirishima. He must've already gone for his morning jog. He had always been an early riser. He decided then that he’d get ready for the day.
It was currently eight, and his Father was coming to fetch him around ten, so he'd have time to make breakfast for himself and say goodbye to Shitty Hair. He undressed, stopping slightly when he noticed his dick, or rather, lack thereof. It had shrunk a lot over the past week, just like that article had told him.
With a shaky hand, he moved it down to feel in between his thighs. Only, rather than feeling balls, a newly formed slit in place. He cursed then retracted his hand, grabbing his usual black graphic-T along with some grey sweatpants. He opted to dry swallow two scent suppressants that morning, instead of placing patches on his neck.
He then made his way into the bathroom to brush his teeth. He grabbed an overnight bag and shoved his toiletry bag inside. He didn't need to pack clothes as he had left some at home before moving into the dorms. He also packed his scent suppressant pills in there, folded inside his face cloth.
He just hoped that his mother wouldn't snoop around in his bags and dig them up, as she tended to do that with all his personal belongings. He zipped up his overnight bag then slung it over his shoulder, making his way towards the kitchen.
Kirishima, the early riser he was, was already in the kitchen, sitting on the counter.
“Morning, Bakugo! Sorry I abandoned ya.” He greeted, with far too much energy.
“Hi.” He rasped out, heading towards the coffee machine, needing some caffeine in his bloodstream to get through the day.
“Are you going home this weekend?” The redhead asked, then took a sip of his protein shake. The blond simply nodded and dropped his bag onto the floor.
“The old hag insisted that I come home every Saturday. I know most go home on Friday but that's not an option for my folks.” He grunted. “Which is why I have to wake up at the ass crack of dawn on Saturdays.” Kirishima nearly choked on his drink.
“Bakugo… it's nine am.”
“Exactly! Far too fuckin’ early for me to be up.” He grumbled, slumping down into one of the stools beside his friend.
“On another note… have you told your parents that you've… yknow?” He asked, trying his best not to rile up the blond any further.
“No. And I'm gonna keep it that way.” The taller boy didn't pry any further, simply nodding with a frown.
After the two had a chat and some porridge that Katsuki whipped up, he got a notification on his phone from his father.
“I gotta go. See you, Shitty Hair.” He gathered his bag once again.
“See ya Monday, Bakugo!” The other boy waved back, smiling a toothy grin.
The blond walked out into the front garden, towards the parking lot where his father's car was parked. His father was at least a little calmer than his mother, but still, he didn't do much to ease tension between the mother and son duo.
He walked towards the car then threw his bag into the back, taking a seat in the back.
“Hello to you too, Katsuki.” Masaru greeted, with a hint of bitterness that was hard to miss.
The blond simply clicked his tongue in annoyance and leaned his head against the window, focusing his attention on the passing scenery instead.
As they drove, the awkward silence started to eat away at his father slightly, so the brunette man attempted small talk.
“Anything exciting happen at school this week?” He asked, adjusting his rear view mirror.
“Nah.” The blond shrugged, keeping certain details to himself, not daring to spill anything about his second gender's sudden appearance.
Once the car pulled up to the Bakugo residence, the omega quickly hopped out, grabbed his bag and ran towards the door, desperate to escape the awkward atmosphere that had been held in the car.
“Your mother's just out buying groceries for us tonight. She should be back in an hour. I'll be in my study if you need me.” And with that, Masaru left, making his way upstairs.
Left alone downstairs, Katsuki decided to head up to his bedroom and complete some more homework. Whilst walking up the stairs, however, he was hit with a familiar stabbing pain that formed in his stomach.
He was so screwed.