Chapter 2: Trust me, I’m an expert on butts!

Yu didn't seem to hear the part about the dogs. She was staring at him, and the panic on her face had shifted into something far more dangerous.

"You..." she started, dropping her voice to a low, careful hiss. "You... were sure that would work?"

Izuku, who up until that moment had been watching everything with the quiet satisfaction of a guy whose plan had panned out, blinked and came back to the real world. Then he nodded with a confidence that spiked her blood pressure straight through the roof.

"I'd say around seventy percent," he admitted, adjusting a tie he wasn't wearing. "But the logic was solid. A firm slap to the affected area is the most classic and well documented training method out there."

Yu's jaw hurt from how hard she was clenching it.

"Logic? Corrective training? Are you telling me you based the decision to touch me like that on a guess?"

"Of course not," Izuku corrected her. "I actually have pretty deep knowledge on the subject."

She crossed her arms over her chest.

"Oh yeah? Enlighten me. What subject are you supposed to be an expert in?"

Izuku straightened up, taking on the air of a scholar about to present his life's work.

"Butts, obviously," he declared. "And before you say anything, my knowledge isn't anecdotal; it's based on years of rigorous study: manga, action figures, and a few late night variety shows. At this point, I'd consider myself a certified expert on butts. And yours," he glanced down for half a second with a professional evaluation, "is top tier."

A dead silence settled over the street. Yu stared at him, trying to process the avalanche of insanity she'd just witnessed. Part of her wanted to slap that smug grin off his face, and another, calmer part wanted to sit down on the dirty asphalt and have a complete breakdown. This kid had spanked her in public, was now grading her with all the calm in the world, and on top of that genuinely believed he was doing her a favor.

"You..." she started again, hunting for a word big enough to cover what she was looking at. "You're... ugh, you're... weird."

"Thanks. I do what I can for the greater good," he replied with a modesty so out of place she wanted to rip her hair out.

The wail of approaching sirens snapped her out of her stupor before she could commit a crime. This was her debut, her first official day on the job. If the cops, or worse, the reporters, found them here arguing about the quality of her butt with some random guy, her career could be over before it even started. The headline wrote itself in her head and drained the color from her face: New hero Mt. Lady caught up in bizarre spanking scandal on debut day.

"Listen to me," she said, stepping dangerously close to him. "No one can know about this, got it? If this gets out, I'm done. My whole career goes down the drain before I've cashed a single paycheck."

Izuku blinked, and the seriousness in her voice finally cut through his analytical bubble. His face shifted into a solemn expression.

"Understood. Your secret doesn't leave here; you have my word."

Yu studied his face, looking for some hidden tell. And in the middle of her panic, she remembered that strange surge of power that had rushed through her when he touched her, the way she'd felt stronger in the instant before shrinking down.

Ambition won out over embarrassment. This weird kid was a risk, and also a walking question mark with a possible shortcut to the top tucked away somewhere inside him.

"We need to get out of here right now," she said, making a decision that would change her life completely. "You can't stay. If the cops find you, they'll start asking you questions about what happened with me, and you," she looked him up and down, "don't look like a good liar."

"But I should probably stay and explain - "

"No!" she cut him off, grabbing him by the arm. "You're not explaining anything to anyone. You're coming with me."

"Where are we going?" he asked, stumbling as she dragged him out of the open area and steered him toward the side street.

"My agency," she said, her mind already racing. "I have a lot of questions, and you have the answers, even if you're too weird to realize it. Move."

They headed for the train station in absolute silence. Yu walked a step ahead at a brisk pace, and Izuku followed close behind, sneaking glances at her back, visibly pleased with his own handiwork. Every time she caught him at it, he'd give her a small nod of approval that made her skin crawl.

"Can you stop doing that?" she snapped without slowing down.

"Doing what?"

"That! The staring!"

"Sorry," Izuku said, with zero trace of regret. "I'm just checking the results; so far there are no side effects and your butt went back to its original state without losing any integrity. I'm impressed."

"Integrity," she repeated under her breath, and picked up the pace.

On the platform, the usual buzz of the outside world made the whole situation feel even more surreal. She bought two tickets and paid for his before he could pull out his wallet. Inside the train they found two seats facing each other, and the train rolled out of the station.

It was Yu who broke the silence.

"Yu Takeyama..." she said. "Though I guess you already know the other one."

"Mt. Lady," Izuku said with a small bow. "Congratulations on your debut. It was incredible; your special move was impressive, and you can tell how much work you put in to get to this level."

"...Thanks," she said, surprised. "You know a lot about Quirks?"

"Just what I read. I was a fan," he corrected himself, and a shadow crossed his face. "My Quirk isn't built for fighting."

"A fan," Yu repeated. "And you said 'was,' past tense. What's that supposed to mean?"

Izuku watched the city pass by the window for a moment before answering.

"When you spend your whole life wishing for one thing and your body hands you the exact opposite, you learn to stop saying it out loud. People get tired of the kid who won't stop dreaming."

"That's depressingly mature for a guy who graded my butt ten minutes ago."

"Comes with the package," he said, and a faint smile tugged at the corner of his lips. "So no, I'm not gonna complain. I made peace with using dog leashes a long time ago."

"Right, the dogs," Yu said, wincing. "What are you gonna do now about the job?"

Izuku shrugged.

"Guess I'll have to find something else. I doubt anyone's gonna trust me with their pet after today; Mrs. Tanaka is going to kill me. Her poodle, Princess Fluffy the Third, has anxiety issues and she's gonna hold a grudge."

Yu felt a stab of guilt that was eclipsed almost immediately by a much more ambitious calculation. This was an opportunity, and a very convenient one.

They got off at her stop and walked a few more blocks to her apartment, located in a simple, functional building in a quiet neighborhood. The inside was bright and spacious, with the understated elegance of someone who barely spent any time at home, the home of a rookie who had clearly poured every last cent into her career.

"It's not much, but it's my base of operations," Yu said, dropping her bag onto a chair. "You want something to drink? I've got water, or well, just water."

"Water's fine, thanks," Izuku said, looking around with curiosity.

While she was in the kitchen, he walked over to a shelf and found photos of her with other girls, probably from her school days, a small glimpse of the person hiding behind the hero image. He was still browsing when she came back with two glasses, and they sat down on the couch, keeping a careful distance between them.

"Alright, Midoriya. Let's talk about your Quirk," she said. "No butt theories; I want the facts. What is it, exactly?"

"It's called Training," he said. "It lets me understand animals' needs and give them simple commands. Up until today I was pretty sure it only worked on animals."

"But it worked on me," she said, her voice still tinged with disbelief. "Um... can you do it again?"

Izuku looked at her and saw the same wild ambition that had driven her during the fight.

"I don't know for sure; I'd never done it to a person before. When you fell and I touched you, my power seemed to understand that your body wanted to be bigger and stronger, so it just granted it. And to reverse it, the same instinct told me that exact spot needed the opposite command."

A faint blush colored her cheeks, and neither of them looked away for even a second.

"And do you think you could improve other things?" she pressed. "Make someone stronger, faster?"

"No idea," Izuku said again, completely absorbed in the puzzle. "I guess it depends on the point of contact. Your butt turned out perfect, so maybe if I touched your elbow, you'd end up with an excellent elbow."

Yu stared at him, unsure whether to feel flattered or insulted. He really was a diamond in the rough.

Meanwhile, Izuku pulled a small, worn out notebook from his back pocket and started scribbling.

"What are you doing now?" Yu asked.

"Taking notes," he said, clicking his pen. "Subject reports a temporary increase in strength, duration unknown, side effects so far limited to enlargement of one buttock and severe emotional distress. All according to standard procedure."

"You just carry a notebook around with you?"

"I used to fill them with hero analyses; it's a habit by now," he said, skipping past some worn pages without letting her see them. "This is the first time in years one of them is about something that actually matters."

Yu set down her glass and leaned forward.

"Do you have any idea what this means? If you can power up a Quirk just by touching someone, even for a few minutes, that's not just any support trick; it's a force multiplier. In the right battle, alongside the right hero, you change the outcome. Agencies would line up to hire you."

"Agencies don't know me," Izuku said. "I usually grow on people slowly, like mold."

"Stop selling yourself short and listen to me," Yu said, leaning a little closer. "You lost your job because of me and you don't have a plan B. I need to understand if your power is more than just enlarging butts. If it's what I think it is, this could be my ticket into the top ten."

The ambition in her voice hit Izuku, who'd quietly buried his own dream months ago, and woke up a feeling he hadn't felt in a long time.

"Here's my proposal," she continued. "Forget the dogs and come work for me. Officially, you'll be my personal assistant. Unofficially," she pointed between the two of them, "you'll be my personal test subject, and I'll be yours. Together we'll figure out the limits of your Quirk. In exchange, you'll get a real paycheck and get closer to the hero world than you ever have before."

The offer was insane and deeply inappropriate, and it was also the best thing anyone had ever said to Izuku.

He saw Mt. Lady, and behind her ambition he saw the hungry rookie holding open a door he'd thought was closed for good.

A slow smile spread across his face, the same one he'd been wearing with his hand still raised in the air after spanking her an hour ago.

"Let me make sure I've got the terms right," he said. "You're offering to pay me to study the most fascinating Quirk I've ever come across, which happens to be yours, with a research partner whose results are already sexy, soft, and - "

"Finish that sentence and the offer's off the table."

"Ahem... and exceptionally qualified," Izuku finished smoothly. "I accept."

"Just like that?" Yu blinked. "You're not even gonna ask about the hours, or the salary, or what 'test subject' actually means in legal terms?"

"You sold me on the paycheck, and you sealed the deal with the part about being closer to the hero world than ever," Izuku said with a shrug. "Everything else is just paperwork."

Yu let out a sigh and narrowed her eyes, already wearing the face of regret.

"One rule," she said, raising a finger. "Don't touch anything without asking first, ever. We do this like professionals."

"Of course. If you don't agree, I won't do it," he nodded with total seriousness. "That's important."

He paused briefly.

"Although now that I think about it... does a spanking count as physical contact or is it its own category? I've never had to research that one."

"Everything counts, Midoriya."

"Even when - "

"Especially then."

"Uh... I didn't even finish, but okay, I get it," he took a sip of water, looking far too pleased with himself. "For the record, this is the most responsible decision I've made all year."

Considering the year he'd had, that wasn't saying much, and for the first time in a long time, it didn't bother him one bit.

Yu let herself fall back against the couch cushion and stared up at the ceiling, seriously wondering what she'd just gotten herself into while, somewhere in the city, a poodle with anxiety issues was running loose, three furious clients were about to discover their pets had vanished, and Izuku Midoriya, certified expert on butts and brand new test subject, had finally found a use for the most useless Quirk in all of Japan.