My Harem System In My Hero Academia

Yami was slouched in his seat, bored out of his mind as Present Mic kept shouting something about gerunds up at the front. 

His voice was way too energetic for a class this lame and this early in the morning. Yami couldn't give less of a shit. 

Yami had already been fluent in English since his previous life, and during his time funnelling money for Iwatani Industries, he talked to plenty of foreigners.

Next to him, Momo sat with her perfect posture, tapping her pen against the desk. 

Her tits pressed up against her blazer every time she leaned forward, and Yami had to stop himself from staring too long. 

The uniform really wasn't doing her any favors—not with her fat tits practically busting out of the blazer and her thighs squeezed into that tight skirt. 

She looked like the kind of girl who'd pretend to be all proper, then moan like a slut if you fucked her the right way or any way for that matter...

"This is way too easy," Momo whispered, her voice was low and irritated. Her lips formed a cute little pout that made Yami want to bite them.

Yami smirked, glancing sideways at her. "Maybe for a nerd like you."

Momo shot him a look, her dark eyes narrowing. "I expected better from U.A. This is basic; even you have better English than him."

"I don't have any idea what he is talking about. Besides. Not everything's about getting A's, princess." Yami leaned back, resting his hands behind his head. "Sometimes you just gotta sit back and chill."

Momo sighed, clearly annoyed. Her tits bounced a little when she adjusted her seat, and Yami caught himself glancing down at the subtle jiggle. 'Damn,' he thought, biting the inside of his cheek to focus.

When class finally ended, the two of them headed to the cafeteria. The place was packed, but they found a spot at one of the corner tables by the window. 

Momo sat across from Yami, crossing her legs and adjusting her skirt. 

That skirt barely covered anything. He knew damn well her panties would be soaked by now if he kept teasing her.

Momo was still pouting, staring at her tray without touching her food. Yami, of course, couldn't let her stew in silence.

He grabbed a fry—crispy and still steaming—and held it up in front of her face with a shit-eating grin.

"Here comes the plane~," he teased, moving it toward her mouth like you'd feed a baby.

Momo's eyes widened. "What the hell are you doing?"

"Feeding my cow," Yami said with a smirk.

Momo's cheeks flushed bright red. "You're disgusting."

"Yeah, but you're still gonna eat it." He wiggled the fry closer to her lips. "Come on. Don't be shy."

Momo huffed, but her lips parted slightly. As soon as the fry got close enough, she leaned forward and bit it, making sure her lips brushed against Yami's fingers. 

She chewed slowly, her gaze never leaving his.

"Good girl," Yami muttered, licking his fingers once he pulled them back. "Knew you couldn't resist."

Momo swallowed the fry, wiping her mouth with a napkin. "You're such a pervert."

"And you love it," Yami shot back, his grin widening. His eyes dipped down to her chest again, watching her tits rise and fall with every breath. "Admit it—you've been thinking about last day all day."

Momo squirmed in her seat, crossing her legs tighter. "Shut up."

Yami leaned across the table. "Bet you've been leaking all day, huh?"

Momo's face turned crimson, her thighs rubbing together under the table. She glanced around nervously, making sure no one was listening.

"Yami, we're in public," she hissed.

"So?" He leaned back, popping another fry into his mouth. "Doesn't mean I can't have some fun."

Momo bit her lip, her eyes dark with frustration and desire. "Augh, Why do I even like you..." she said as she stared at the bag of fries as if begging Yami to keep feeding her.

Momo sighed, hiding her smile behind her hand. "...I swear, you're gonna be the death of me."

On the other side of the cafeteria, waiting in line like a goddamn loser, was Mineta. 

His tray held a double bacon burger so greasy it might've clogged his arteries on sight, and instead of fries, he'd grabbed a pile of onion rings that reeked of fried death.

But Mineta wasn't thinking about his meal.

No, his beady little eyes were locked on Yami and Momo across the room.

Yami was feeding Momo fries, teasing her in a way that had her all flustered and blushing. 

And Momo—fuck—Momo was eating it up. Her tits bounced every time she shifted in her seat, her skirt riding up just enough to make Mineta bite his lip and squirm uncomfortably.

He clenched his fist so hard it made his onion rings wobble on the tray.

'That smug bastard…' Mineta thought. His eyes narrowed as he watched Yami toss a fry into his mouth with a cocky grin. 'Who the hell does he think he is? He's got the hottest girl in class wrapped around his finger!'

Mineta's jealousy boiled over, and right then and there, he made a vow:

'Iwatani Yami is my goddamn archrival.'

As if he stood a chance.

After lunch, the class returned to the homeroom, and the sound of chatter and talking filled the air as friend groups began to form. 

Yami and Momo, however, remained in their own bubble, indifferent to the social energy around them. 

It wasn't as much because they weren't sociable. Yami had a good reputation during middle school, and Momo was president of as many things as she could. 

Still, when asked to approach or respond, both chose the latter.

Yami leaned back in his chair, arms crossed, while Momo scribbled in her notebook, explaining her newest invention.

"It's a shockwave grenade," Momo said, her voice full with enthusiasm. "It doesn't have any fragments or harmful debris. Just pure force to push enemies back without lethal damage."

Yami raised an eyebrow, "So... how does it even work?"

Momo's eyes lit up with excitement as she leaned closer to Yami. She flipped her notebook around, showing him a neatly sketched diagram of the grenade. 

The page was filled with detailed notes, equations, and cross-sections of the device. Her handwriting was messy, and for a moment, Yami thought he had seen a cum-stain...

"It's quite simple in concept," Momo began, tapping her pen against the drawing. "The grenade combines compressed gas and a piezoelectric charge."

Yami cocked an eyebrow, smirking slightly. "I follow"

"As you know, certain materials generate an electric charge when they are mechanically stressed—like quartz or certain ceramics." 

"In this case, the grenade's core contains a disc made from a piezoelectric material. When the grenade is activated, the compressed gas rapidly expands and applies mechanical pressure to the disc."

"So, it's like squeezing a stress ball that shoots out energy?" Yami asked, amused.

Momo giggled softly, nodding. "That's... one way to think of it. But instead of releasing the energy all at once, the device is designed to create a focused shockwave. The outer casing is reinforced to direct the force outward in a controlled arc."

Yami leaned in closer, resting his chin on his hand. "And what happens when it goes off?"

"When the piezoelectric disc is triggered, it generates a high-voltage pulse. That pulse then ignites a secondary reaction in the compressed gas, causing it to expand rapidly and create a shockwave." 

"It's strong enough to knock opponents off their feet or push them back several meters, up to 10 meters for an 80kg adult man."

"And no shrapnel?" Yami asked, narrowing his eyes at the diagram.

Momo shook her head confidently. "None. The casing is designed to stay intact. The whole point is to create a non-lethal crowd-control tool. It's perfect for dealing with multiple enemies without causing permanent harm."

Their conversation was cut short when the classroom door burst open. A familiar booming voice echoed through the room.

"I HAVE COME! "

"I HAVE COME THROUGH THE DOOR LIKE NORMAL PERSON!"

All Might's larger-than-life body filled the room.

Besides a few, everyone in the room erupted in cheers, their excitement practically shaking the walls. Yami and Momo exchanged a glance but remained silent, their expressions neutral.

"HERO BASIC TRAINING!" All Might announced, his arms spread wide. "THIS CLASS WILL PUT YOU THROUGH ALL SORTS OF SPECIAL TRAINING TO MOLD YOU INTO HEROES!"

The room grew quiet, the weight of his words sinking in.

"… IT ALSO GIVES A LOT OF CREDITS!" All Might added with a grin.

The class burst into cheers again.

"ANYWAY! NO TIME TO DALLY! TODAY'S ACTIVITY IS THIS!" All Might struck a dramatic pose, holding up a remote. "BATTLE TRAINING!"

Gasps and murmurs filled the room as he continued.

"And for that, you'll need these!" All Might gestured toward the wall as a section of it slid open, revealing a row of metallic cabinets. 

Each cabinet held suitcases labeled with numbers from 1 to 20, shining under the fluorescent lights.

The students' excitement reached its peak as they realized what was inside.

"YOUR HERO COSTUMES!" All Might declared. "DESIGNED TO FIT YOUR REQUESTS AND SUPPORT YOUR QUIRKS!"

Even Yami and Momo couldn't hide their interest. Momo's eyes gleamed as she imagined her suit in action, while Yami tilted his head slightly, curious about how his design had turned out.

"ONCE YOU'VE CHANGED, MEET AT GROUND BETA IN RANKING ORDER!" All Might said, his voice booming with authority. "LET'S SEE WHAT YOU'RE MADE OF!"

The students eagerly grabbed their suitcases, rushing off to the changing rooms. Momo held hers close to her chest, her excitement barely contained while Yami just thought about how her hero costume would look with her now... huge assets.

As they walked to the changing rooms, Momo glanced at Yami. "Think it turned out how you wanted?"

Yami smirked, his golden eyes glinting. "Guess we'll find out."

[Spoiler]