Because, when someone tells you to keep a secret. The last thing they mean, is spilling it right away to the guy that hates your guts. Or the one with a good backstory.

I own nothing, Rated M for future chapters.

GenderBent!IzukuxKatsuki. Alpha, Beta, Omega dynamics because I am on a kick of it lately.

Enjoy!

OoOoOo

"Are you All-might's secret love child?"

Well, that was a loaded question. Though maybe not wholly unexpected. Eventually someone was going to assume, or to ask. A formerly 'quirkless' Omega did not go around smashing things just like All Might and not receive a bit of attention.

Izuku blinked, feeling her face heat up to extreme measures. Partly out of being alone with the Stoic Alpha, and partly because it wasn't every day that someone accused your mother of basically being a slut.

…or, that you were forced to go along with it because All Might did say that no one could know about One-for-all. The safety of others seemed a touch more important than her pride.

She straightened, face a brilliant shade of red, and opened her mouth. A stuttering reply was all she could manage.

"Y-ye…yes…" the new holder of One-for-all managed, silently praying her mother wouldn't come from around the corner and slap her silly.

"Yes, my mother had an affair with All Might, and you know…hahahaha…. I came out…. You know…. Later."

The way her voice cracked at the end was so awkward. Even for her. Yet, the Elemental Alpha didn't seem to be phased by it at all.

"I see," Todoroki said more to himself than her.

"Please don't tell anyone," Izuku said quietly, nearly filled to the brim with panic. If her mother found out, she was as good as grounded until she was thirty.

"It's supposed to be a secret." She finished lamely, trailing off to look toward the ground. The Omega winced as she smelled her own distress and outright fear. The Alpha noticed too, for he took a step backward.

"I won't," he promised lowly, and she believed him. Maybe her nature was too trusting, or it was the fact that he really didn't have a reason to go spouting out about her mother's supposed affair with the legendary hero All Might.

"My father is a powerful hero as well," The Alpha boy continued, inclining his head slightly. "I was born to suit his needs."

The thought 'Trauma alert' flashed through her mind, but Izuku did her best to listen to Todoroki with an open heart.

OoOoOo

Crimson eyes stared at the green-haired girl in absolute disbelief. He'd been minding his own damn business, sort of, just looking for a drink of water. He'd seen the half-and-half jackass take Deku to the side.

Not that he cared when the Omega went off with some random Alpha. There was no need to protect her that lead him down the similar path they had walked.

However, his thoughts churned with what he had just heard. It made so much fucking sense now. Why that shitty-Deku never fought back! Why she had pretended not to possess her power. Why her quirk was hurting her now. She had never used it in her childhood like she was supposed to.

She'd been hiding her quirk, because of the shame it would bring on her family. It was so fucking clear now! That was the real reason that Mr. Midoryia went to work overseas and never came back. It wasn't due to his job in underwater welding, he had been unable to live under the same roof as the wife that had left him for All Might.

Wait… that meant…

…. The fucking shit-nerd was All Might's daughter!

He had heard it from her own mouth.

Clearly, she had taken after her mother, in appearance. Yet, she had inherited her father's quirk. That was why she had concealed it from him. At such a young age, he would have been jealous, sure, but also if she had used it… everyone would have known. Deku hadn't been lying to him to make a fool of him, she'd been trying to save face for her mother.

She was only using it now, because her dream of being a hero had been too great. He knew how determined Deku could be. He had mocked her for it often enough, but now there was a burning sense of respect for her. To have concealed something like that, for so long…

Even when he had made it harder on her everyday…

Now that was a willpower that earned even Bakugou's respect.

He had been more than content to leave her be, for the most part, after her secondary nature had come into play. Alphas had no need to challenge Omegas. It didn't make a whole lot of sense for him to continue to bully her as he once had. In fact, his ire toward her had cooled tremendously, until he had spotted her at the entrance exam. Until he had seen the powerful quirk she'd been hiding all this time.

And he was beset by the sudden urge, to take Izuku back into his pack. That shitty Deku, who had not lied to him for fun, should be accepted into his good graces once more. There had been a time, where she trailed after him everywhere. He had always been too proud to admit that he missed those times, even as he pushed her further and further away.

Before grade school, his nature had been apparent long before it should have been. He'd gathered his group of Betas to his side, knowing that they could never be half the Alpha he was, even if they turned out to be Alphas later on.

Then, there had been the one and only Deku. Now it made sense why he had been so quick to snap her up as children. Some part of him must have recognized her Omega nature, buried underneath the bright smile and unruly curls.

The day she had stood up to him, stating that she'd never forgive him for picking on the only other quirkless kid they knew. His Alpha side had taken it as a severing of ties. A challenge against him, and a threat. He had been too young then, to see what it had truly been.

An Omega seeking to bring her Alpha back in line.

Such things were common, especially in the young. Omegas were the peace keepers and they kept Alphas from losing control. Redirecting the rage and softening it until it was manageable. Deku had always had that effect on him, which still pissed him off to this day. Except now, that they required fewer members in a pack, he saw the value in it.

As small children they needed several packmates to stabilize and grow. As young adults, An Alpha could be held in check by up to two Betas and an Omega. In adulthood, once he reached it. A mate would be sufficient. Beta or Omega. Or even another Alpha, if their tempers could mesh at their worst.

He scowled as he realized that Deku had been 'pack-less' as well as 'quirkless' for many years. He turned a blind eye, for once being mature enough not to say anything, when his mother was the one to mark Deku's clothes after their falling out. It had been shortly after her father had left. Well, the man that was married to her mother. Mr. Midoryia.

He could still remember Deku coming over in the mornings on the way to school, and his mother lifting her up to rub her cheek against the girl's. He pretended that he knew nothing about it. However, Izuku's mother was only a Beta, and they needed the protection of some Alpha to keep the less than noble sorts from attempting to push in.

He'd seen the purchased sprays that Deku kept in her bag. Even though he had bullied her, and mocked her, he had never said a word about her need for Synthetic Alpha scent. Nor had he ever taken them. It was for her protection.

It made sense now, with her 'Father' unable to bear being near his unfaithful wife. And her real Father, couldn't say who she was for fear of every villain coming out of the wood work to get her.

Even here, Deku had made friends, but she hadn't been extended offers into any packs. Most likely, because of the synthetic sprays she still used. It made them think she already had an Alpha, and to be a Beta in her pack they would have to get permission from the Alpha.

His hands clenched of their own accord, and Bakugou realized that he felt remorse over his treatment of her. And, he acknowledged that he had missed her. He had been young, and cruel. He should have known better, but he hadn't. Now, he did, and he wanted to bring Izuku back.

He didn't give two shits about her being All Might's daughter. He just wanted to be her Alpha again.

He wanted his Omega to come home.

Home to where she belonged. Home to the scent of him on her clothes so that others would know she was his pack member. Home….so that he could keep her. He had planned to do so when they were kids, after he made it to a pro-hero. He knew how much Deku loved heroes, and he was going to be the greatest one ever.

Just for her.

Though no one quite knew it, Katsuki Bakugou was hopelessly in love with Izuku Midoryia.

OoOoOo

The fight with Todoroki had left her broken. Recovery girl had refused to heal all her wounds completely, as a lesson to her of the damage that could come from recklessness. Yet, she hadn't been trying to be reckless. She'd been trying to reach Shouto. The Alpha was all alone and in pain.

Izuku knew exactly how that felt. Well, Minus the Alpha part.

His scent had reeked of desperation and loneliness. But in that one fragile second, where he had unleashed all of his power against her, he had been smiling. The physical pain she was in, felt as if it might have been well worth it. Simply because she knew she had managed to reach him beyond the wounds and scars of the past.

If she were exceedingly lucky, and the thought made her blush slightly, he might… offer to form a pack with her. She was extremely hopeful, but did not fully expect anything from it. After all, her last pack had been when she was about six, and the Alpha was…

Kacchan.

She frowned lightly, staring at her bandages as the puffiness of her eyelids faded. She'd cried to All Might in a long-winded apology, but as always, the Alpha had understood. And, what was even more miraculous was that he had praised her for doing what was right, over what was beneficial to her score.

She sniffled, absently, her eyes prickling with tears as she thought about it once more. The saltiness of her tears filled the room, and she blinked, trying to keep them to a minimum.

"Does it still hurt?"

She jumped slightly, wincing as pain shot through her arm. Emerald eyes widened, as they stared into Crimson orbs which watched her far too intently for her liking.

'Speak of the devil,' she thought sagely, and shook her head in response to his question.

"A little, but it's not awful, or anything."

She could smell the Alpha scent on him, and it made her slightly uncomfortable. He wouldn't try to pick a fight with her in the recovery room, would he? Speaking of which, where was Uraraka and Iida when she needed them? Then again, the Speed Beta was trying like crazy to get Uraraka to accept him as a packmate. She thought the Gravity Alpha might do just that, here soon.

"Tch," he made a noise in the back of his throat, but it lacked its usual dismissal of her. Izuku froze, and looked at him, her instinct insisted that something was different.

The school had cameras, right? Just in case he tried to smother her with a pillow? Right? Nervously she glanced to her left and right. Hm… no cameras….

Well, crap.

She watched as he scented the air, sensing her nervousness and the beginnings of distress.

"Calm your tits," The Alpha growled, red eyes flashing. "I'm not gonna beat you up in the freaking hospital."

"Recovery room." She corrected tonelessly.

"What the fuck ever." He huffed, and glanced over at her again. She tensed as he reached into his coat pocket, and pulled out a long silver vial.

Izuku gasped, flushing to the roots of her hair.

"The smell's worn off," he commented, ignoring her surprise. "I thought you might need this again."

He walked a few steps closer, until he was at the side of her bed. Her messy green hair had a bandage poking out from around her head. She reached her less injured hand out for the vial. A question at the tip of her tongue, as she awkwardly made a motion to grab it.

Her fingers couldn't quite manage and it fell downward, bouncing slightly on the bed.

"Fuck," Bakugou swore, and she was shocked when his hands clasped around her extended one. Far too quickly for her to pull away.

She sat there, in mute witness, to him nearly mentally cataloging her wounded limb.

"Your quirk really does a number on you," he muttered lowly, and she almost felt as if she were caught in some strange dimension. Or still under some awesome anesthetic drugs.

She cleared her throat, feeling vaguely weirded-out by just how tender Kacchan was being. He was never like this. Not with her. She'd seen it before, when one of his Betas had been hurt in a freak biking accident on the way to school. Bakugou had guarded them for about a week, making certain they could get around all right, and that everyone gave Shikigou a wide berth.

Granted, that was also the week that he cut her hair, after gluing some of it to the back of the chair. It was also a reason that Izuku learned to always put her hair up around Bakugou.

"Uh… yeah," She said after a moment, gingerly attempting to extract her hand from his. He allowed it, without tightening his grip on her arm.

She looked down, and felt the blush on her cheeks. The silver vial seemed to twinkle up at her, mockingly.

"So… you knew." Izuku started, without preamble.

Bakugou was always a straight forward Alpha, and she could smell the discomfort coming from both of them.

"Yeah, I knew."

She nodded, a quick jerking movement,

"How long?"

"Since second grade."

"Ah."

Then the silence stretched between them, and she knew that they were not looking at each other anymore. It was a huge stigma to be completely pack-less, unless you were an adult in search of a mate. It implied that you were defective, or inferior in some way.

She reached with her less injured hand, for the vial once more. Her fingers trembled as she tried to close them around the cylinder with little success.

"Oh, for fuck's sake." Bakugou growled, and suddenly she was staring with wide eyes at the ceiling.

He had knocked her back onto her bed, and she could feel the bed dip with his weight. Green met a smoky looking crimson. She could only watch, stunned again for the second time today, as he crawled over her. His knees braced on either side of hers, and then he was rubbing his head against hers. Gently, and mindful of the bandages. His nose soon found its way to the crook of her neck, and she could hear him groan in satisfaction.

Her mind, however, was having difficulty comprehending what was happening. Because it looked like, for all the world, that Kacchan was scent marking her. The way he had when they were kids. Well, granted, they had both been standing usually as kids, but the action was the same.

She wanted to ask him, but could not find the words to speak the question out loud. He was taking his time, nipping across the skin of her neck, and biting at her shoulder, but not enough to harm in any way. He drew back, only to continue the other side, and soon he was rubbing his forehead against hers.

Her lips parted in a silent 'o'.

And just as suddenly as it had started, it was over. The Alpha moved from the bed, sliding off the edge to place his feet back on the floor.

The sound of small feet, drew their attention away from one another.

"Oh," Recovery girl exclaimed lightly, "it's you."

Crimson eyes narrowed, and his posture became slightly defensive.

"Now, now, calm down. I was just wondering who her Alpha was." The old woman chided gently. "You'd better take more care to scent mark more often, honey. The scent was so faded, I almost thought it was fake."

Izuku paled, Katsuki growled. The comment hit far too close to home, for comfort.

"She's mine. My pack."

The old woman looked exasperated, and more than a little put out.

"Honestly, kids today, I know that. Now. I was just warning you for future reference. Clearly, she had an Alpha." Recovery girl prattled on. "Who wouldn't want an adorable Omega like this as a packmate?"

No one failed to notice, how Bakugou continued to stand at the side of the bed, muscles tensed and expression fierce. Recovery girl smothered a chuckle and hid a smile behind her hand. Such an affectionate Alpha. She would never have guessed it from the rumors about the boy. However, her old eyes knew a deep bond when she saw one. It would explain why she didn't scent a Beta anywhere on young Midoryia. Maybe they had not agreed on someone yet, and it could have been that the Alpha was a bit too possessive to share.

It wasn't unheard of.

"Well, you will have to go for now, her bandages need changed, and I want to check her incision."

Green eyes swung toward Crimson, and Bakugou nodded his head slightly. It was completely unintentional, but it looked almost as if Izuku were confirming she had permission with her Alpha.

What a cute couple! The old Beta hummed softly to herself as she pushed the Explosive blonde out of the room. Recovery girl had no way of knowing that Izuku's stomach was trying to flip itself into knots. Or that Katsuki was a little too assumptive on how easy it would be to get Deku back as his pack Omega.

OoOoOo

She's been poked and prodded until she feels a bit like a cow at the local market. Finally, recovery girl informed her, that she could leave. With a stern lecture on not using the synthetic Alpha spray, and to just Omega up and ask for her Alpha to scent her. Because other Alpha's might get the wrong idea, that she was in-between Alphas.

Izuku never wanted to see Recovery girl waggle her eyebrows at her, in that way, ever again. It was mortifying beyond all belief.

Luckily, Kacchan's scent had faded, quite a lot, from the sterile stench of disinfectant and fresh linens. It had been two days, and Izuku was still at a loss for why he would have scent marked her. Maybe it was out of a shred of kindness, since she hadn't been able to even hold the spray? That actually would make sense for Kacchan.

It made her smile softly, thinking that he had grown quite a lot since they were children. When they were very young, he would have been more inclined to pee on her, laugh about it, and then pretend he was doing her a favor. Well, she hoped he wouldn't really have peed on her, but with Alphas it was really hard to tell sometimes.

Uraraka came bounding up to her, the moment she walked out the doors, and Iida was not far behind, casting furtive glances at the Gravity Alpha. Izuku internally cooed at him. The Beta had it so bad for her friend.

It was the scent that hit her first, and she gasped out loud, glancing between the pair. Iida smelled of jasmine, cinnamon, and Alpha.

He smelled of Ochacho.

Emerald eyes widened, and she tapped her forehead to Iida's chest, signifying her congratulations. The Beta smiled, though it was still a bit stiff. Then again, that was just Iida. Uraraka slung an arm around his shoulders, and Izuku watched as he all but melted against the female Alpha.

"He's my Beta," the brown-haired girl exclaimed excitedly.

"I know!" Izuku confirmed, and grinned widely. "I am happy for you two."

"Thank you." Iida said, bowing formally. Izuku returned the gesture.

It was then, that she noticed Ochacho's nose wrinkled, and the Alpha scented the air again. Her warm gaze turned sharp, and she looked Izuku over carefully.

"When you can," she offered brightly, but there was a hard note to her words, "you need to find your Alpha and have them mark you again."

Izuku blinked, and froze.

"You smell… available."

Available was the polite way of saying, unprotected. She swallowed heavily, trying not to let her heart hammer in her chest. Holder of All-for-One or not, Izuku was still an Omega, and she still needed an Alpha's protection. Especially in a world were villains would find any reason to hurt of subjugate someone for their own wicked intentions.

Midoriya smiled broadly.

"You're right. I was actually just on my way to see him."

"Oh?!" Uraraka leapt on the bit of new information like a dog that had been promised a juicy bone. "Your Alpha is a male? Who is he?"

A startled noise worked its way out of Izuku's throat, at the unintentional stumble. She normally played the pronoun game, and never gave any specific details about her supposed 'Alpha'. However, her mind was still reeling with Kaachan's pack declaration.

"Alpha," Iida chided, as he placed a hand on her shoulder, pulling her away from the startled Omega. "You are invading her privacy too much."

Being balanced by the Beta, Uraraka stopped suddenly, and flashed a sheepish grin toward Izuku.

"Sorry," she said sincerely, "I was merely curious. I didn't mean to interrogate you."

Izuku laughed it off, internally sweating over the fact that she didn't have an Alpha, and she would have to get all the way home, before she could use the synthetic spray.

OoOoOo

She made it within 500 feet of the gate, when Shotou had stopped her. A pensive expression was on his face, and he stared at her with his mis-matched eyes. Very pretty eyes, by Izuku's opinion.

"I wish to form a pack with you." He stated, apropos of nothing.

Izuku blinked. She turned around, to look about her, and then pointed to her chest.

"Me?"

"Yes, you." The stoic Alpha confirmed, with a slight grin to the left side of his lips.

Huh.

Izuku did not look entirely convinced.

"Me, me?"

"I'm not even sure what that means," he stated, waiting patiently for her reply.

She shook her head, hoping to clear it, and gazed at him fully.

"You want to form a pack with me?" She clarified, proud of herself for not stuttering like crazy. Her heart was thumping loudly in her chest, out of excitement.

"I wish to be your Alpha," Todoroki stated boldly, and not the slightest bit afraid of rejection. After all, Izuku Midoryia understood what it was like. To be the child of a famous hero, and to be alone. He knew the scent on her was false. He had been able to tell the first day in class together. His father had trained him on such things. He had been able to pick it out in an instant.

And, after their battle and her words, Todoroki wanted the Omega to be with him. He would give her the protection she lacked. He had failed with his mother, being too young at the time. However, he would not fail Midoryia.

"Uh…." She replied eloquently.

His mis-matched eyes continued to stare at her.

"Okay?" Izuku said, not sure of what Omegas usually did in this situation. She had the feeling that Shotou didn't know either, and that made her feel slightly better.

He stepped forward, closing the gap between them. Like Kacchan, he rubbed his cheek against hers, marking her with his scent. It was different than Bakugou's though, and his touch did not illicit feelings of excitement and the faintest flickers of arousal. Todoroki's touch was systematic, and nearly business like. It was oddly comfortable, because it did not make her feel those things.

He nipped lightly at her neck, and licked a patch of skin over her scent glands. She giggled slightly at the unexpected feel of his tongue on her skin.

She noticed that he smiled at her reaction.

When he pulled away, he ruffled her mop of curls and looked down at her. A lightness was in his gaze that made her feel needed and special.

"Omega." He called her title fondly, kindly, and in a way, that acknowledged her new station in his life.

OoOoOo

The next morning, she waited patiently by the gates of the Academy. Though her new packmate's scent had not fully faded, it was best to scent mark every day, as Recovery girl had warned her about. Izuku rocked back and forth on the heels of her feet to the tips of her toes.

Her hands grasped her backpack straps tightly, and she smiled widely. She could see the others waiting for their Alphas as well. And she and Tenya had been speaking before Uraraka had come and rubbed against him, dragging him to class. She'd waved at them, and promised she'd be right there.

She was just waiting on her Alpha.

Momo stopped by briefly, to grab Mineta by his ear. The Alpha female had that Beta wrapped around her little finger. And, Izuku was under the impression that their relationship involved some S&M things, because Mineta always eagerly spouted off about 'play' and 'being a good boy'. Momo always sneered and called him scum, but there was an oddly loving tone the pair shared.

Izuku couldn't understand it, but it wasn't her pack; so, she minded her own business.

She stretched for a moment, allowing her hands to let go of the straps of her backpack. The pull in her arm was slightly uncomfortable still, but it would fade in time.

Arms encircled her from behind, and she brought her arms down and leaned into the embrace. A familiar scent, calms her before she can startle away. It tells her mind that she is safe. This is a known smell. It smells oddly of ash, and smoke. But, half of Todoroki is fire and he did say that he trained with his fire side.

She smiled, and turned, allowing her face to bury into her Alpha's chest. She rubbed her cheek along his chest, nearly purring in happiness.

A low rumble of approval met her actions. She could feel Todoroki's fingers, combing through her hair. A gesture of affection that she found she adored instantly.

This was what having a pack was like. The sudden elation and warmth. The feeling of security and protection she had been missing out on with the sprays. The sensation her mother had tried to explain to her, but words failed to live up to this. This simple, and wonderful feeling.

She could feel Shouto's head rub against the top of hers. And she laughed, gently, at the slightly tickling feeling it gave. He seemed to not want to let go of her, as his whole body felt as if it were encasing hers.

"Alpha," she nearly chirped, a contented purr in her chest.

Another pass of his cheek across her hair, and his fingers tangle slightly in her wavy locks.

"Omega." He rumbles out, and the satisfaction that drips from his tone prickles at her senses.

Izuku froze, eyes snapping open, as the voice of Katsuki Bakugou registered in her ears. A noise of alarm and surprise freezes inside of a shout, trapped within her throat. No sound escapes.

She pulls back, staring into a blazing Crimson gaze, and she takes a note from her mother's book. She stares. Because it is not the sweet mis-matched eyes of a stoic Alpha she is gazing into. And, the Alpha that tormented her for most of her childhood is embracing her like they have been packmates for years.

Or maybe it was that Kacchan did not look as if he were about to murder her.

"What the fuck is with that look?" Katsuki demanded, but there was no real heat to the words. He took a moment to rub his face against hers.

Slack, with shock, Izuku let him. Her head tilted slightly to the side out of a submissive tendency due to her secondary nature.

'…Brain? Brain, where did you go?'

Bakugou's nose crinkled with distaste.

"You reek of that synthetic shit again. Cut that crap out, I'm here now. You don't fucking need that stuff anymore."

He rubbed against her harder, nipping at her neck.

"Ugh. This one almost smells like that half-and half bastard." Crimson eyes narrowed at her balefully. "Never buy this fucking brand again. It's awful. You hear me? Never buy it again."

Dimly, speech slowly started to return to her mind. And she opened, and then closed her mouth several times.

"I will not buy it," she promised.

He seemed content with her answer, and went right back to erasing Todorki's scent with his own. Honestly, Izuku saw a few problems with that. One. It really was Todoroki's scent and technically he was her pack Alpha now. Which created problem Two, Clearly, Bakugou had been serious before when he claimed her…. Which made him her pack Alpha now.

So… which Alpha did she follow? Which was she packed up with? She whimpered a bit in the back of her throat. It caused Katsuki to lick the same patch, that Todoroki had licked just yesterday, of her skin. Rumbling lowly.

Then everything sort of went… blank.

Because, as if her thoughts alone had summoned him somehow, she could see Todoroki, her actual Alpha (Second Alpha? Her brain would hash it out later), over Bakugou's shoulder, coming up toward them. A look of fury on his face. He probably thought Kacchan was picking on her again.

Because prior to a few days ago, Katsuki was still always picking on Midoryia.

Whatever the reason, she took one look between the pair of them, and did what her dear sweet mother was known to do.

Izuku promptly fainted.