My Harem System In My Hero Academia

Mineta was shaking as he crouched behind a pile of rubble on the third floor. 

His traps and sticky balls covered the area, but he could still hear Yami moving above him, clawing through the ceiling like some kind of monster. Every step sent shivers down his spine.

"You can't get me!" Mineta shouted, trying to sound brave but his voice cracked. "I-I've got traps everywhere! You won't win!"

From above, Yami's voice echoed. "Traps won't save you, Mineta. You're out of your league."

Mineta gritted his teeth, grabbing another handful of his sticky ball hair. He threw them randomly into the air, hoping one would hit Yami. 

The balls bounced off walls, beams, and the floor, but Yami's movements were too quick for any to connect, and since neither could see each other, strength became the determining factor.

Mineta peeked out, his heart sinking as he saw Yami drop loudly to the floor, breaking the tiles of the floor under his weight. 

Yami moved precisely, stepping around every trap as if he'd set them himself.

"You call this a challenge?" Yami said, almost amused. "You're not even trying; Momo would have blown me up by now."

Mineta first got angry. 'And he calls her by name!' he thought, then panicked, throwing more sticky balls. 

Yami twisted, dodging each one with ease. The balls stuck to walls and floors, but none came close to hitting their target. 

Mineta's breathing grew ragged as he saw Yami get closer.

Finally, Yami stepped in front of the rubble Mineta was hiding, towering over him. 

His golden eyes glowed faintly in the dark as if he was a panther, sharp and piercing. Mineta froze, the fear coursing through him like ice.

"You think hiding will save you?" Yami whispered, leaning down so their faces were inches apart. "I'm the last thing you'll ever see if you try something stupid again."

Mineta's eyes rolled back as he passed out, collapsing in a heap.

Yami straightened, sighing. "Pathetic."

Meanwhile, in the CCTV basement, the rest of the class watched the battle unfold on the monitors. 

The dim room was filled with the sound of shifting chairs and murmured questions.

"Wait, who's the villain here again?" Mina asked, squinting at the screen.

Kirishima scratched his head. "I think it's Momo and Mineta… but Iwatani doesn't look like a hero at all right now..."

All Might clapped his hands to draw attention back to him. "Alright, class! Let's hear your analysis of the match so far. Bakugo, you're up first."

Bakugo snorted, leaning back in his chair. "Tch. The idiot's wasting time. If it were me, I'd just blow through all those traps and be done with it. He's overthinking everything."

Iida adjusted his glasses, standing up in defence of Yami. "I disagree, Bakugo." 

"While Iwatani may appear to be taking his time, his cautious approach is logical. He's up against Yaoyorozu, whose Quirk excels in preparation and strategy, and Mineta, whose sticky orbs are highly effective for area control. This makes Yami the underdog."

"Exactly!" Uraraka chimed in. "He's being smart about it. If he just rushed in, he'd get stuck or blinded by those traps!"

The class fell silent as All Might grinned. "Good observations, everyone! Let's see how this plays out!"

Back inside the building, Yami sighed as he tied Mineta's unconscious body up with the blue ribbon belt from his hero costume. 

The small rat was surprisingly heavy, and Yami quickly wrapped him onto a beam in the corner of the third floor.

Yami took a moment to look over the area. The third floor was a mess of traps and sticky balls. 

Every staircase leading up to the higher floors had been sealed off, leaving no obvious way forward. 

Yami noticed faint smudges of blood on some of Mineta's balls—evidence that the little pervert had put real effort into setting this up.

"Hm... at least he tried," Yami muttered, looking at Mineta and sighing.

With his left hand petrified, Yami moved toward one of the windows covered in heavy cloth and broke through it. 

Sunlight poured into the dim floor, illuminating the space around him. Yami climbed out onto the exterior of the building, carefully gripping the ledges as he began to ascend.

'Should've done this since before, but she probably expects this,' he thought, his golden eyes scanning the walls for hidden traps. 'Better stay sharp.'

The climb to the fifth floor wasn't difficult, but Yami moved slowly, wary of any tricks Momo might have left for him outside. 

When he reached a window, he paused, studying it closely. It was partially covered in cloth, but he noticed faint scratches on the sill—evidence of movement.

"She's been here."

Deciding to take the risk, Yami broke the window and crawled inside. The moment his feet touched the tiled bathroom floor, a flashbang grenade shot up from the ground and exploded in front of him. 

The blinding light and deafening noise filled the room, but Yami was faster. His head petrified just in time, shielding him from the effects.

"Not bad, Momo," he said, depetrifying his eyes as the smoke cleared. 

Carefully, Yami stepped out of the bathroom and into one of the fifth-floor's hallways.

The sight before him was a maze of metal wires and traps. Almost every square inch of the hallway was rigged, with faint glimmers of wire catching the sparse light. It was a nightmare to navigate.

Yami crouched low, his sharp eyes following the paths of the wires. Just as he jumped to crawl along the ceiling to avoid them, he heard a soft click. 

His instincts screamed at him to move, but before he could react, a grenade was shot and thrown into the hallway, bouncing off the walls toward him.

The grenade glowed faintly purple before detonating. The shockwave hit Yami with incredible force, throwing him backwards into the bathroom. He slammed into a metal stall, denting it with the impact.

"Shockwave grenades," wincing as he got back to his feet. His petrified hands had absorbed most of the impact, but the force still shocked him.

"Good idea, Momo. But they could be better. They explode on a timer, not on impact."

Shaking off the disorientation, Yami moved cautiously back into the hallway.

"She's trying to lure me into the traps," he thought. "Fine. Let's see how she handles me when I don't play by the rules."

Using his petrified hands, Yami began slicing through the wires carefully, clearing a narrow path through the hallway. 

The traps triggered harmlessly, grenades and other devices clattering to the floor as he deactivated them one by one. 

Some acted successfully and shot at him, so even then, Yami suffered a little damage, nothing he couldn't tank.

Eventually, Yami reached the center of the fifth floor, where he found a large open room. 

It was dark, save for faint beams of light seeping through cracks in the ceiling. 

In the very center of the room was a rocket-looking object, the "nuclear" bomb. Momo was in front of it, her wooden Kendo sword in hand.

Her eyes narrowed as she faced him. "You made it. I was starting to think you'd give up after the seventh explosion."

Yami smirked, stepping in. "Give up? Not my style. Besides, I figured you'd want to handle this personally."

Momo raised her sword, her stance solid and practised. "Just as expected."

"I wouldn't have it any other way," Yami replied confidently. He crouched slightly, folding his red gi to better petrify his arms, his hands becoming obsidian blades again. 

"Let's see what you've got." Yami said, but he started to feel a bit... sleepy.

Momo smirked as she noticed Yami starting to slow down, his exhaustion finally showing after throwing too many grenades at him. 

His body looked tired, his steps heavy, but his sharp eyes still locked onto her. 'Oh, how much I love those eyes... I wished after we fought he could just fuck me like I'm a villain who deserves to be...'

Yami rushed at Momo, taking her out of the trance; Momo created a gas mask from her cleavage, sliding it over her face. Her big tits jiggled with the quick movement, the tight red top barely holding them in place.

"Just as expected," Momo said, creating another shockwave grenade from the fat in her body. 

The grenade formed right between her big, sweaty tits, the flesh squeezing around it before she hurled it at Yami.

He rushed forward, but Momo was ready. She detonated the grenade near her feet, blasting herself backwards and putting some distance between them. 

Her fat ass bounced as she hit the ground, but she was on her feet fast, pulling out more tricks. 

Two more grenades formed in her left hand, her thick thighs flexing as she threw them at Yami.

Yami ducked, dodging the grenades easily as he lunged toward her. Still, his punch was blocked by the wooden Kendo sword she'd created earlier. 

The impact made her big tits bounce violently, threatening to spill out of her skimpy costume.

"How do you like my grenades?" Momo taunted as she swung her sword again. Yami blocked it with his left petrified arm, and as he did so, Momo spun on her heels and kicked Yami, aiming for his stomach.

Yami managed to grab her leg when she tried to kick him. Her juicy thigh was soft but strong under his grip, and for a split second, he admired how Momo sculpted her body to his liking.

But Momo wasn't done. From her thigh, a flashbang grenade violently shot out and triggered instantly. 

The explosion blinded Yami, but he didn't let go of her leg. She quickly followed up by pouring oil from her ankle, making the floor slick and hard to stand on.

Yami groaned, feeling the effects of the gas in her grenades. "You added nerve agents," he muttered, realizing why he felt so weak and slow. 

His mind raced. He had to end this fast, or he'd pass out.

He decided to keep things simple. No fancy moves. Just brute strength. 

Yami charged at her, his petrified hands swinging, but Momo blocked with her sword. 

Her nipples were hard, poking through the fabric of her top, and her sweat made her skin glisten under the light coming from the cracked ceiling.

The fight got closer and more intense, their bodies colliding as they grappled and exchanged blows. 

Yami managed to steer them toward the slick oil she'd poured earlier. When Momo tried to step back, her foot slipped, and she fell flat on her back. 

Her big tits jiggled violently as she hit the ground, her short skirt flipping up to reveal her lacy black panties and the soft curve of her round ass.

Yami didn't waste time. He rushed toward the rocket-shaped bomb in the middle of the room, ignoring how his body felt like it was shutting down. Just as he reached for it, Momo's voice echoed through the room.

"Hellzone Grenade!"

Momo had thrown herself into one of the corners of the room and pulled a hidden string, and dozens of shockwave grenades shot out from every corner of the room, aimed straight at him. 

They exploded all at once, the force blasting Yami into the wall like a ragdoll.

Dust and debris filled the air as Yami pushed himself up from the rubble. 

His shirt was torn to shreds, revealing his massive, rock-hard chest and thick, defined muscles. His pants hung low on his hips, showing off his strong abs.

"That actually hurt," Yami said, shaking the dust off.

Momo, still on the ground, tried to push herself up, but she was too weak. 

Her body had shrunk—her fat tits were noticeably smaller, her ass no longer the thick, juicy masterpiece it had been. She looked worn out, her pale face still dripping with sweat.

"Hah… I went anemic…" Momo whispered and looked up at Yami, her eyes half-lidded.

Yami sighed, shaking his head. "You fought hard," he said, walking over to the bomb to secure it. 

Once he'd won the match, he crouched next to her, turning her onto her side so her smaller tits wouldn't get squished.

Through the speakers, All Might's booming voice rang out. "The Hero Team… WINS!"

Yami looked down at Momo, her chest rising and falling heavily as she tried to catch her breath. He smirked. "Not bad, cow. Not bad at all." Yami said, then fell unconscious on her lap.