A/N: The chapters switch POV - odd chapters are Katsuki - even chapters are Izuku. Since alphas are the dominant and powerful secondary sex, all pro heroes are alphas. Those born with lower-level quirks or quirkless always present as omega or beta. Katsuki Bakugo planned on being hero partners with his childhood friend, Izuku Midoriya, until that friend turned out quirkless. After years of bullying, Katsuki presents as alpha and finally understands that he can be with an omega Izuku in another way. He wants to repair their relationship, but then Izuku makes it into UA with an insanely powerful quirk. He was an alpha all along? Or is he?
Izuku Midoriya presented as an omega, but was given a powerful quirk. He hides the fact that he's an omega like he hides the origin of One For All - until his heat comes. He has to go through it, and omegas need the presence of an alpha. With a whole class full of alphas, who will he choose?
Chapter 1 - We're Supposed to be Partners!
"What the fuck is wrong, you little shit?"
An answer never came, nor was one expected. The limp body in his arms hadn't responded to anything he'd done or said in the training ground, so Katsuki didn't expect an answer just because he was now carrying that body across the school grounds toward the main building.
Leave it to goddamned Deku to fucking pass out in the middle of training. He hadn't even hit Deku that badly with a blast. The little fucker had dodged most of it. Good thing, too, or he'd have singed off those damned green eyebrows. Or worse. Shithead.
He paused on the sidewalk to shift Deku's weight. Fuck, but this asshole had gotten heavy. Fucking muscles or whatever shit. Katsuki glanced down with a growl, ready to bite Deku on his fucking nose for making him, fucking Katsuki Bakugo, future number one hero, carry his dead ass halfway across campus.
He stopped though, feeling his expression soften. Despite having passed out for whatever fucking reason, Deku looked fully at peace. His head had slumped over against Katsuki's chest, his cheek and part of his nose pressing into the soft t-shirt Katsuki wore sometimes to spar. The full cheek sprinkled with freckles looked as soft as ever, sending the urge through Katsuki to press his lips against those damned freckles and taste every single one of them.
The thought sent a growl through his body and he shook his head. He couldn't have those thoughts anymore. This damned fucker had fooled him already, and he wasn't about to let his inner feelings get riled up once more. Not the way Deku had been doing consistently for their entire life.
An alpha. A fucking alpha.
He wasn't supposed to be an alpha.
He felt his own alpha growl at the fact. Whether that was just an alpha response to another alpha, or his thwarted desires to have Deku as his omega one day, Katsuki couldn't tell. Nor did he want to know. There was nothing to do about it now. Other than to direct all his anger at the limp form in his arms.
Stupid Deku.
Thinking about how pissed he was, however, was not getting Deku to Recovery Girl, so he kept trudging across the grounds to the door of their school, his mind a whirl of memories he didn't want to think about.
"Kacchan! When we get our quirks, we're gonna be a super power duo!"
"I can't wait to be your partner, Kacchan! We're gonna be as awesome as All Might!"
" You're already amazing!" said in that awed voice Izuku could affect, his big and green eyes staring up at Katsuki. "You're gonna get an amazing quirk and be a million times more amazing! Me too! And we'll be amazing together, though I'll never be as amazing as you!"
Katsuki gritted his teeth as he somehow managed to shift Deku's weight enough to free a hand to yank open the door. Izuku was such an idiot when they were kids. Always following him around and praising him to the stars. Sure, it was flattering, and he was happy that Izuku admired him so much. He was even willing to be that little asshole's partner.
Actually, at four years old, that's all he wanted for his life. Two things. To be a top pro hero and to be Deku's partner. They were going to keep the world safe from all villains.
Then Deku let him down.
Okay, Katsuki now knew that it wasn't Deku's fault. He had the maturity to recognize that, at least. Four-year-old Katsuki, however, blamed Deku. He was quirkless. The little jerk never developed one. How the fuck could he and Deku be hero partners when it was obvious Deku was never going to be a hero? All his dreams were shattered that day when Deku told him, barely coherent through the sobbing.
Katsuki winced as he strode down the hall. He'd been so angry with Deku and had shoved the crying boy onto the floor. Fuck, he was still ashamed at his reaction all this time after.
All he saw – then – was that there wouldn't be two alphas taking over the hero world. He'd be alone.
His mother tried to console him as he blasted things inside his room. His quirk had only manifested a few weeks before, so his explosions weren't the powerhouse blasts he could summon now. They barely singed his things. Still, Mitsuki Bakugo sighed at the fact that she'd have to replace Katsuki's All Might comforter and the newish curtains on his windows.
" Pup," she crooned, "it's not going to be as bad as you think…"
"We're supposed to be partners!" he screeched, his toddler voice lifting in octaves that had his mother wincing.
A sly grin he couldn't decipher in his young mind crossed her face. "You can still be partners, my little explosive one. Just not hero ones."
He didn't understand at the time. He and Deku were close friends and planned to be future heroes together. That's all he knew. Katsuki had only a vague understanding of secondary sexes, of alphas and omegas and betas. Now, he knew his mother was suggesting that Deku would make a good omega for him. They'd be partners, but in a different sense. Mitsuki saw how Izuku worshipped her son. She knew that quirkless people always went omega. It's how it was.
Powerful hero-level quirks were always alphas. If you had a quirk, but it wasn't powerful or something you could use as a pro-hero, you could go either beta or omega. Heroes needed to be powerful, and alphas were the secondary sex with strong powers. If an omega ever achieved the impossible level of hero, everyone would look down on them. They wouldn't be considered a good omega.
Omegas were the dams that bore children. Not that they were considered weak, per se, because having, raising, and whelping pups was a damned hard thing to do. They were feminine, however. Even the male omegas. Curvy, wide hips and soft features were the ideal. A muscular, big, and strong omega would be undesirable.
Katsuki shook his head again. He'd turned the corner of the hallway leading to Recovery Girl's nursing station. He wore a scowl, which wasn't unusual for him, but this was for the way his fucking life turned out. All because of the shithead he was carrying in his arms, hoping to get him healed from whatever it was that knocked him out.
It was no surprise that Katsuki turned alpha. What else would he have been? His quirk had grown in power and he knew he was on the path to being a hero. The only taint to his plan was the pain in his heart put there by Deku's betrayal. Tinged with guilt. Ever since the bastard told him he wouldn't have a quirk, Katsuki Bakugo bullied the living shit out of him, ignoring the flashes of hurt in Deku's eyes every time he said something mean, every time he shoved, every time he punched. Because he knew it wasn't a flash of hurt from physical pain. It was betrayal.
But, didn't Deku betray him?
He regretted that stupid childhood logic, especially because Deku didn't get it. He wanted nothing to do with the little green-haired freak. Continuing their friendship meant seeing Deku every day. Seeing him every day only drove home that betrayal. That break of trust. That break of promise.
What a fucking ignorant asshole he'd been.
Katsuki understood his mother's words eventually (and not just those first words – she was friends with Inko, Deku's mother – and constantly hounded her son to 'play nice and be kind to Izuku…he's a nice boy and you'll appreciate that one day'). He understood them not long after presenting. Deku presented as an omega, as expected.
That's when Katsuki noticed his scent the first time.
It wasn't that before presenting children had no sense of smell. He always knew Izuku smelled of earth and sunshine and summer days. Before their friendship dissolved, they'd copy the adults by scenting each other – rubbing the undeveloped scent glands on their wrists on each other. It was nice to go to sleep with that very faint smell of Izuku surrounding him.
When one presented, however, those scent glands opened and nostrils became more sensitive to them. Katsuki discovered how sweet Izuku smelled. That earthy smell deepened, the sunshine smell brightened, the summer day smell expanded, and it was all underlined by another scent – an enticing sliver of something like jasmine. Rich and heady, intoxicating and alluring, and Katsuki understood. His mother had been warning him for years, trying to get him to make up with Izuku and apologize.
Because Katsuki understood, now, what a desirable omega was. He understood that Izuku would be a perfect omega for him. Hadn't Izuku always looked up to and admired him? If Katsuki had listened to his mother, swallowed his pride, apologized, repaired that friendship, he could have courted Izuku, young as they were. They would have had both their parents' blessings.
As a young teenager, though, Katsuki Bakugo had no idea how to apologize. For years he'd received praise about his quirk, building up an arrogance in him that impeded most of his social life. Add to the fact that his body produced a shit ton of nitro-glycerin that enhanced his temper a hundredfold, and he was an insufferable little prick.
He had enough self-awareness now to acknowledge that.
What also stopped him from apologizing was stupid Izuku himself. The little shit still thought he could be a hero. Not just a hero, but also Katsuki's hero partner. It made him furious to think of it. Izuku, quirkless and omega, thinking he could be a hero? It was fucking insane. Not only that, it was downright dangerous. The entrance exam alone, to any of the hero schools, would kill the dumb fucker. And this stupid asshole wanted UA? There was no way in hell.
Instead of apologizing as a normal person would, Katsuki increased the angry outbursts, insults, and bullying, because now he, Katsuki fucking Bakugo, was scared shitless that Izuku would try to get into UA and get himself killed. Once he knocked that fucking dream out of Izuku's head, he told himself, he would apologize and grovel at the omega's feet for forgiveness. In a perfect world, this plan would work, he could court Izuku, and he could eventually be the top hero in the world and fall asleep every night to a content, sweet-smelling, perfect omega.
And, just like their childhood dream of being a pro-hero duo, Deku had to fucking destroy this new dream too.
They could have a perfect fucking life if Deku got his shit together.
That asshole had somehow lied to him, his family, everyone. That asshole was really an alpha. With some insane fucking quirk that was uncontrolled but all-powerful. He couldn't be an omega with a quirk like that. It confused the fuck out of Katsuki, because with Deku's alluring scent (all too quickly hidden by scent blockers after Deku presented) he had to be an omega. The alpha in Katsuki was enamored with the green haired boy, though he didn't show it yet. An alpha would not attract another alpha. What the hell was that all about?
Either way, no matter how much he apologized to Deku, there was no way they'd mate. That pissed him off more than anything.
His tumultuous thoughts stopped as he got to Recovery Girl's door, which was ajar. He nudged it fully open with his foot, thankful to find the room empty of all but the healer. She was typing at her computer, but turned around at the sound. Nothing ever fazed the older woman. She took in the sight of Katsuki standing in the door with Deku in his arms and just gave a curt nod. "On the bed," she said in her kind voice.
With a gentleness that would likely surprise his friends (ugh, he cringed inside at the thought of having friends), he lay Izuku on the bed closest to Recovery Girl so she wouldn't have to walk far. "He just collapsed while we were sparring," he said in a gruff voice.
She hummed, bending over to get a closer look at the unconscious boy on the bed. "How hard did you hit him?"
He bit back an angry response. "I didn't. That's the weird thing. He dodged one of my blasts. He hadn't even engaged his quirk. We weren't fully going at each other. He jumped to the side, gave a little squeal, and then fell over. He was breathing normal, had a strong heartbeat, he didn't look like he was stressed. He looked asleep."
The woman smoothed back the curls from Izuku's forehead in a gesture that made Katsuki jealous with an aching need to do the same. He growled down that impulse as he watched her lips extend to plant a kiss on the smooth, exposed skin. Nothing happened, though Katsuki had no idea what he expected.
"Can you go fetch All Might for me, young Bakugo?" she asked.
"Is Deku okay?"
"I think he will be, but I need to speak with All Might about his problem."
"You know what it is? What's wrong with him?" he demanded, his tone rude.
It didn't faze her. "Nothing you need to worry about just yet, my dear. All Might, please."
Recovery Girl was one of the UA staff that Katsuki had complete respect for, so he strode out of the room to fetch the old man. She hadn't seemed anxious, so maybe whatever happened to Deku wasn't serious.
All Might was, thankfully, in his office, and followed Katsuki back to the nurses' office at a quick pace. Another thing for Katsuki to be jealous of – the way the hero he looked up to more than anyone loved Deku. So what if the little green shit had a power quirk? Fuck him and his fucking sunshine smile.
Katsuki hung back by the door when they entered the nurse's office. He didn't know what he hoped to gain by it, but maybe Recovery Girl wouldn't notice him and he'd hear whatever she told All Might. Unfortunately, his hearing wasn't that great – what with all the explosions he created – and Recovery Girl spoke in a low tone to the pro hero, who stood towering over the bed, his head bowed.
When All Might asked, "So, do we let it happen? I'll have to tell his teachers…" Recovery Girl shushed him, glancing over her shoulder at Katsuki. All Might followed her gaze. "Ah, young Bakugo!" he boomed. "Thank you for bringing young Midoriya here. You may go now."
"What's wrong with him?" he demanded, though he doubted they'd give him an answer.
"It is nothing to worry about. Young Midoriya will be just fine!"
The smile All Might gave him was the same one he smiled when in battle. Katsuki didn't believe it for a second. All Might had once said that when things look their worst, he would smile and continue to fight. This was that smile, so Katsuki knew that Deku wasn't okay.
The pair by the bed, however, stared at Katsuki without saying a word. The smile on All Might's face seemed to beam light into the room. Recovery Girl's stony face didn't twitch a muscle. They may have well have been statues and Katsuki knew that he could stand there all day without getting an answer, even if he blasted everything he could get his hands on.
"Tch, fine!" he snarled. Slamming the door as he stomped out wasn't as satisfying as it should have been. Damn Deku. Always fucking things up. He stormed outside in order to create blasts without damaging anything or anyone. Anything to get rid of this pent up worry caused by the only person who mattered to him in the world. The only person who fucked everything up in his world. Damn fucking Deku!