Sex Quirks (My Hero Academia)

Poll Winner

Themes: Big Dick, Fucked Silly, Marathon Sex

Summary: After hearing that Izuku was diagnosed as Quirkless via pinkie toe x-ray, a test known for not being completely reliable, All Might insists he gets a second opinion. After an examination by Recovery Girl, it's discovered that Izuku does indeed have a Quirk, albeit a sexual one. Given Midnight also has a sexual quirk, albeit minor, she's brought in to help out. Alas for poor Izuku, the only way to awaken a sexual quirk... is through sex.

-x-X-x-

Sex Quirks. They were kind of one of those things everyone knew about, but nobody really talked about. Especially around children for obvious reasons. And yet… they existed. Sort of an open secret of sorts. Sex Quirks were Quirks that didn’t really come online until someone had sex. A person would register as having a Quirk, but until they had sex, they wouldn’t be able to use it.

Or… in some cases, if one were to use an antiquated test like the pinkie toe X-Ray, then someone with a Sex Quirk might be registered as Quirkless instead.

That was apparently what had happened to Izuku Midoriya. Truth be told, the last couple days had been something of a whirlwind for the poor young man. Ever since he’d gotten into UA, he’d been riding high. Being All Might’s protégé and inheritor was also pretty great, but being accepted into UA’s Hero Class was how Izuku KNEW that he was finally on the road to making his dream come true.

And then, he and All Might had been talking and it had come up that Izuku’s Quirkless diagnosis had come from the pinkie toe X-Ray, a test that had been largely debunked to the point of being phased out of most medical facilities in the decade since Izuku had been given it.

Immediately, All Might had insisted Izuku be examined by Recovery Girl, and the old school nurse had gone on to discover that Izuku did in fact have a Quirk… and since it had never shown itself, he obviously had a Sex Quirk. Which had in turn led to Izuku finding out about Sex Quirks… and being told how exactly to activate his.

“You don’t need to be nervous, Midoriya. I’ll take good care of you, alright?”

And that in turn had led Izuku to today. Standing there in a conference room looking at the R-Rated Pro Hero Midnight, one of UA’s teachers. Grinning at him with her hands on her hips, the gorgeous heroine cocks an eyebrow at him.

“Though… it’s okay if you’d rather not. Just say the word and we don’t have to do anything you don’t want to.”

Izuku is half-tempted to take her up on that offer. But… something stays his hand. And no, it’s not that she’s absolutely beautiful and he really, really wants to fuck her. That IS true, but Izuku wouldn’t allow that impulse to make his decisions for him. No… the fact is, not every Sex Quirk is ALL about sex. Sure, they usually have something to do with sex, but plenty of people have Sex Quirks that can be used for Hero Work as well.

Midnight is a great example of this, in fact. And that… that was why Izuku had to go through with this. Because if there was really some latent power inside of him that he could combine with One for All to devastating effects, then he owed it to not just himself, but the people of Japan to unlock it and begin training with it as fast as humanly possible.

… And also, Midnight was absolutely beautiful and he really, really wanted to fuck her.

“N-No… I mean, no. I do want to do this. I’m ready, ma’am.”

Midnight giggles as she stalks up to him.

“You don’t have to call me ma’am, darling. Just call me Midnight.”

“A-Alright… if you call me Deku.”

That gets a raised eyebrow from the heroine, but Izuku doesn’t back down. He knows Deku means dummy, but he doesn’t care. He’s turned Katsuki’s name for him into his strength. Seemingly seeing his resolve and determination in his eyes, Midnight slowly nods, a note of respect entering her tone.

“Hm, alright then Deku. Let’s begin.”

Without missing a beat, the R-Rated Pro Hero drops into a crouch right in front of him. Bowed legs, ass below her knees, the works. Izuku gulps as she quickly extracts his already half-hard cock from its confines, cooing over it all the while.

“Oh my. What an impressive specimen, Deku. You have quite a lot to be proud of down here~”

Despite her teasing tone, Izuku doesn’t get the impression that she’s lying to him or just trying to make him feel good. He gulps at the compliment, even as Midnight begins to go down on him, taking him in between her lips and descending along his rapidly hardening length.

Humming so as to send vibrations up and down his shaft, she looks up into his eyes and smiles around his dick, even as her lips stretch to an almost obscene degree the bigger and harder he gets. Eventually, she’s bobbing up and down his girth like a professional, swallowing continuously so as to suppress her gag reflex.

Izuku just stands there and enjoys the ride. He can still hardly believe this is even happening, let alone bring himself to participate. Truthfully, he’s afraid to even touch Midnight, lest she get angry at him for this or that and use her Quirk to knock him out. After all, he didn’t need to be conscious for her to awaken his Quirk.

They’d offered that as an option to Izuku, to just go to sleep and wake up with his Sex Quirk active, but Izuku had rejected that proposal. He wanted to be awake for this… and not just because of how hot Midnight was. Though that was a large part of it.

It’s not long before Izuku can’t hold back anymore anyways though. Finally, with a loud groan, he seeks to warn his teacher of what’s coming.

“M-Midnight… I’m getting close!”

Far from pulling off or anything like the inexperienced young man is expecting… Midnight doubles down. She sucks HARDER at his throbbing mast, and her hands even come up to hold his shaft steady and fondle his balls. Izuku tips over the edge with an even louder groan than before and explodes into Midnight’s mouth and throat not but a moment later.

To her credit, she swallows every last drop without issue and without fail. She doesn’t spill anything as she drinks down his cum, gulping away like there’s no tomorrow. Izuku nearly doubles over her as he feels his balls tighten before finally being wrung empty. Then, it’s over.

Except… he doesn’t feel any different. Blinking, Izuku pulls back as Midnight does the same, the Pro Hero rising from her couch and standing up, only to begin removing her clothing.

“Um… I don’t think it worked, Midnight.”

Looking at him, the heroine laughs huskily, already having exposed her chest and quickly removing the rest of her outfit as well.

“Of course not, Deku. That was just the warmup. The only way to awaken a Sex Quirk is through sex… and oral doesn’t count.”

O-Oh. So that meant… Izuku blushes hard but doesn’t protest. He’d assumed when Midnight started blowing him that they wouldn’t be going all the way. But apparently, he’d assumed wrong. Once the Pro Hero is completely naked, she wastes no time in hopping up onto the edge of the conference table, spreading her legs wide and fondling her own breasts as she gives him a lascivious grin.

“Ready for the Main Event, Deku? I’m all yours, stud~”

Needless to say, he doesn’t even need to wait long to recover from his first release. Having a gorgeous woman like Midnight naked and presenting herself to him like this has Izuku rock hard again in moments. Almost in a daze, he steps forward into her embrace, letting her wrap her arms around his head and guide him down to her bosom.

Even as Izuku begins to worship her breasts with his mouth and tongue, he also grabs Midnight by her thighs and guides his cock into her slick, wet folds. He might be a virgin, but he’s not an idiot. Tab D goes into Slot V, all that jazz. With a muffled groan into her chest, he sinks his virgin cock right into Midnight’s sex, leaving her to moan wantonly as she throws her head backwards and arches her spine.

His hands move from her thighs to her hips in order to hold her steady even as Izuku begins fucking her hard and fast. He tries to stay respectful, tries to maintain a slow and reverent pace all things considered… but it’s impossible. Midnight’s body is pure sin, and being inside of her makes it far too hard for Izuku to hold back.

Luckily for him, Midnight isn’t expecting respect. In fact…

“Yesss~ Give it to me, Deku. Fuck me with that big fat cock of yours! Don’t you dare hold back! Give me every last inch of your dick, fill me to the brim! Awaken, young man! Awaken your Sex Quirk and use it on ME!”

Izuku is pretty sure that’s not supposed to be the plan, but at the same time it’s clear that Midnight is really feeling herself at this point. In all fairness, Izuku is feeling HIMSELF as well. He couldn’t hold back even if he wanted to, and with the beautiful older woman giving him permission to go full steam ahead, he doesn’t want to.

PLAP! PLAP! PLAP!

The sounds of flesh slapping against flesh fill the conference room and then some, growing progressively louder as Izuku pounds into Midnight nonstop. In response, Midnight clings to him, her arms wrapped around his neck and her legs wrapped around his waist as she gleefully accepts every last inch of his throbbing member. Izuku loses track of time, and he also loses track of just how many times Midnight cums on his cock, but finally… he can hold back no longer.

With a loud groan, the young man cums at long last, finishing inside of Midnight and filling her with his seed. This time around, Izuku does feel something upon release. He feels a strange sense fill him and having been given a direct order by his teacher to use it on her, Izuku directs that energy he’s feeling into Midnight.

The effect is immediate. Her eyes widen and then roll back in her head, her tongue sticking straight out of her open mouth as she chokes on her own spit. Her body shakes and spasms beyond just from pleasure and for a moment Izuku thinks he’s accidentally killed her.

Pulling back, Izuku watches with wide eyes as his Quirk, the true one and not the one All Might gave him, finally activates and gets used for the first time. Fortunately, whatever he’s able to do… it doesn’t kill or harm Midnight in any meaningful way. But it does alter her, Izuku quickly realizes.

The R-Rated Pro Hero slowly recovers, shuddering and twitching. Her limbs are vibrating, but she nevertheless hops down off of the table despite the shakiness in her legs. As she stands there wobbling, Midnight looks down at herself… and blinks dumbly.

“Huh…”

“Um… I don’t understand. What is my Quirk, exactly?”

Humming, Midnight considers herself for a moment longer, running her hands up and down her transformed body. Then, she bounces up and down a few times before grinning at Izuku wickedly.

“If I had to guess… I’d say you have some sort of Sexual Healing Quirk, Deku. Maybe more specifically Sexual Rejuvenation.”

Oh. That… well, that was better than what he’d initially thought. Because the woman in front of him is suddenly a lot younger than she was before they’d fucked. Midnight had to be at least twenty or thirty years his senior before today, but now she looks like she’s only about ten years older than him.

She looked gorgeous before to be fair, but he hadn’t realized that the Pro Hero was on the other side of her prime until he sees her now, looking like a million yen. Giggling at his ogling, Midnight does a little twirl.

“You didn’t just give me my superficial youth back, Deku. You healed every bit of my aches and pains. Hm, and my scars are all gone as well. Basically, every old injury I ever got from Hero Work, every single ounce of aging… has been reverse. I feel like I’m in my prime again, back to peak health… though I’ll have to check with Recovery Girl to make sure, I suppose.”

Midnight pauses… and then gives him a hungry look.

“Alternatively… we keep fucking and test all this out ourselves~”

Izuku blinks and blushes as the de-aged Midnight sashays her hips, swaying her even more perfect body back and forth.

“A-Ah… a-are you sure that’s a good idea?”

Pouting at him, Midnight turns around and bends over the conference table, lifting her ass high into the air as she arches her back and looks at him over her shoulder.

“Are you saying you don’t want more of this, Mi-dor-iya?”

Gulping, Izuku shakes his head and surges forward. He should probably put a stop to this, but he’s not the authority figure here anyways, so why should it fall to him. Midnight is in charge, and if she thinks it’s safe… fuck it. Grabbing onto the even more beautiful Pro Hero by her hips, Izuku slams back into her from behind and proceeds to fuck her hard and fast once more.

He's even stronger than he was before, though Izuku doesn’t really notice it. It turns out, his Sex Quirk goes both ways and has been supercharged by One for All. Between being All Might’s Inheritor and the Quirk he was naturally born with, Izuku is set up to become the most powerful man on Earth… so long as he keeps having sex regularly.

But for now, Izuku doesn’t know that. What he does know is that Midnight’s new body is tighter and hotter than her old one, and she’s even better now than she was before. He can’t help himself, nor can he get enough of her… and neither can she get enough of him.

They wind up fucking for the next several hours, really ruining the conference room. And in the end, they only stop because despite Izuku’s Quirks, he can still reach his limits apparently, and they literally fuck each other into unconsciousness.

Worth it.