My Harem System In My Hero Academia

After their first day of classes ended, Yami and Momo slipped off into a quiet, empty bathroom on U.A.'s campus. 

Momo had been struggling all day with the plug keeping Yami's thick cum inside her, and she couldn't take it anymore; she was a walking ticking bomb, but instead of exploding, she would cum and squirt in public.

Momo sat on the toilet inside the stall, her cheeks flushed with embarrassment and lust as Yami watched her. 

Yami leaned against the stall door, his golden eyes watching her fat tits through her uniform. He smirked as she fumbled with the plug, her hands trembling slightly as she slowly tried to pull it off.

With a soft pop, Momo removed the plug, and a thick stream of hot, creamy semen began pouring out of her swollen pussy, splattering into the toilet water below. 

She let out a quiet, shaky moan as her body released the built-up pressure.

Yami crossed his arms, smiling. "Feels better, doesn't it?"

Momo nodded, her dark eyes hazy as she glanced up at him. "I… I couldn't hold it anymore," she admitted, her voice barely above a whisper. 

Her thighs trembled as more of his cum flowed out, mixed with her own juices, Momo was at the edge of cumming, but she held strong since she didn't want to look too vulnerable to Yami, even if it was too late for that.

Yami chuckled, running a hand through his messy black hair. "You've been walking around with all that inside you all day, huh? You're something else, Momo."

She blushed harder, biting her lip as she tried to stay quiet. Her body was still sensitive from their night together, and even the act of releasing his cum was enough to make her pussy throb. 

"It's not my fault," she whispered, almost defensively. "You're the one who filled me up so much."

Yami stepped closer, leaning down until his face was level with hers. "And you're the one who begged for it," he said, teasing her, "You begged for each load, didn't you?"

Momo's heart raced as she looked into his sharp, golden eyes. She felt completely exposed, not just physically but emotionally. 

She wanted him again, right there, but she knew better. "We… we shouldn't," she stammered, her voice trembling with the desire to have a rough fuck, and the fear of having sex in their first day of school.

Yami reached out, brushing a strand of her black hair away from her face. "You're right," he said, his tone softening slightly. "Not here. Not now."

Momo nodded, her chest rising and falling as she tried to steady her breathing. 

She couldn't help but feel disappointed, even though she knew he was right. Having sex on the first day at U.A. would be risky, stupid, and hot...

Once Momo had cleaned herself up and absorbed the plug as fat for her ass, Momo stood up, adjusting her uniform and trying to regain her composure. 

Yami opened the stall door for her, smirking as he held it open.

"Ready to head home?" he asked.

Momo nodded, her cheeks still red. "Yeah… let's go."

As they walked through U.A.'s empty hallways, Yami couldn't keep his hands to himself. 

His palm slapped hard on Momo's fat, jiggling ass, making a loud smack that echoed through the corridor.

Momo gasped, her cheeks turning a deep red. "Y-Yami!" she whispered, looking around nervously to make sure no one saw.

But Yami wasn't done. He grabbed both of her thick asscheeks through her skirt, squeezing them hard as if testing the ripeness of fruit. 

His fingers dug into her soft flesh, pulling her closer until her hips pressed against his thigh.

"Such a fat fucking ass," Yami growled, his voice low and rough in her ear. "You really are my cow. Just a walking piece of meat for me to grope, fuck, and fill with cum whenever I want."

Momo whimpered, her thighs pressing together as his words sent a wave of heat straight to her womb. 

Her pussy clenched around nothing, on her now empty pussy, holding back an orgasm that threatened to make her squirt.

"You're gonna make me soak through my panties," Momo whispered, biting her lip to stifle a moan.

Yami chuckled, squeezing her ass even harder. Her skirt barely covered her enormous ass, the fabric stretched tight over her thick hips and juicy, round ass. 

Every step she took made her ass bounce and jiggle, begging for attention and to be fucked.

"Good," Yami muttered, giving her ass another hard smack. "I like seeing my cow wet and needy."

Momo shivered, her heart pounding as she tried to focus on walking. But Yami's hands didn't let up. 

His fingers kept digging in her ass, spreading her cheeks through the skirt, occasionally slipping down to brush against the curve of her inner thighs.

They walked like that until they reached the front gates, where Iida, Midoriya, and Ochako were chatting. 

Just as Yami and Momo approached, they overheard Ochako say, "...But 'Deku'... well, it just sounds like 'do your best'!! I kinda like it."

Yami's sharp golden eyes locked onto Uraraka. 

She was short but curvy, her U.A. uniform hugging her wide hips and thick thighs. 

Her tits weren't as massive as Momo's or Angela's, but her round tits still strained against the blazer, threatening to pop a button.

Her ass wasn't small either. It was as ridiculously huge as Momo's, but it had a nice, plump curve that made Yami's cock twitch in his pants. 

He could imagine bending her over a desk, pulling up that skirt, and pounding her until she screamed his name.

Just then, the system chimed in with a new mission.

====

[New Mission: Ride or Die!]

Objective: Get Ochako Uraraka to ride your cock.

Time Limit: 1 Month.

Reward: Quirk Upgrade — Elemental Battle Modes.

Failure: Minus one to a random stat.

====

Yami smirked to himself. 'One month to make that sweet little ass bounce on my cock? Easy.'

Momo noticed his smirk and tugged on his sleeve. "What are you thinking about now?" she asked, narrowing her eyes.

"Nothing important," Yami replied casually. "Just… setting some goals."

Momo gave him a suspicious look but didn't press further. They climbed into her sleek black limousine, settling into the soft leather seats. 

Momo sat close to Yami, her thick thighs pressing against his, and he couldn't help but admire how her skirt rode up, showing a peek of her creamy, smooth skin.

The ride was quiet, but Momo kept shifting in her seat. Her massive ass pressed into the cushion, spreading slightly with each movement. 

She crossed her legs, her thighs squeezing together as she adjusted to the emptiness inside her pussy, already missing Yami's cum that stayed right where it belonged.

Yami noticed her squirming and smirked. "Still feeling full, huh?"

Momo nodded, her cheeks flushed. "It's… It was a lot," she admitted softly. "I can still feel it sloshing inside me every time we hit a bump."

Yami leaned over, his hand sliding up her thigh. His fingers brushed against the hem of her skirt, teasing her. 

"Maybe you like it," he whispered to her ear. "Maybe you like being stuffed with my cum, walking around with my load inside you."

Momo whimpered, her thighs trembling under his touch. "Yami…"

Before she could say more, the limo pulled up in front of Yami's house. The driver opened the door, and Yami stepped out, adjusting his pants to hide his growing erection.

Before he left, Momo grabbed his hand, her dark eyes locking onto his. "Hey," she said softly. "Can you make us a new training schedule? Now that we're at U.A. And leave at five? I need to reschedule training, studies, all of it."

Yami nodded. "Yeah. I'll work on it tomorrow."

Momo smiled, squeezing his hand. "Thanks. See you tomorrow."

The limo drove off, leaving Yami standing in front of his house. He stretched his arms over his head, cracking his neck as he walked up the steps.

The moment he stepped inside, the familiar scent of home hit him—lavender, fresh linen, and something sweet.

Angela stood in the kitchen, her black kimono barely holding her massive tits in place. 

The fabric clung to her curvaceous body, and Yami's eyes immediately locked onto her chest. Her massive udders swayed slightly as she moved, the outline of her hard nipples visible through the thin fabric.

Angela turned when she heard the door, a warm smile spreading across her face. "Welcome home, sweetheart."

Yami didn't say a word. He walked straight up to her, grabbed a handful of her thick ass through the kimono, and gave it a firm squeeze. 

Angela let out a soft gasp, her green eyes sparkling with amusement.

"Someone's in a good mood," Angela teased, leaning into his touch.

Yami smirked, his hands moving up to her massive tits. He pulled open her kimono, letting those heavy, milk-filled breasts spill out. Her nipples were already hard, and Yami licked his lips.

"Need a drink," Yami muttered, leaning down to take one of her nipples into his mouth.

Angela moaned softly, her fingers running through his hair as he sucked on her tit. Her warm, creamy milk flowed onto his tongue, sweet and comforting.

"Drink as much as you want," Angela whispered, her voice dripping with lust. "You've had a long day."

Yami drank deeply, his hands kneading her soft, heavy tits. Angela's body trembled with pleasure as she felt his tongue flick over her sensitive nipple.

When he finally pulled away, a thin trail of milk dripped from his lips. He licked it off, smirking up at her.

"Delicious," Yami said, giving her ass another hard smack. "You've got the best milk."

Angela blushed, pulling her kimono closed again. "You always say that."

"Because it's true," Yami replied, wrapping his arms around her waist and pulling her close. "You're perfect."

Angela leaned up to kiss him, her lips soft and sweet. "And you're my perfect boy."

Yami chuckled, kissing her forehead. "Let's eat something. Then I'm going to need more milk."

Angela giggled, walking back to the kitchen. Her massive ass swayed with each step, and Yami couldn't take his eyes off her.

Life was good. And it was only going to get better.

After dinner, Yami and Angela got into their usual routine. Angela ended up bent over the kitchen table, moaning like crazy, while Yami pounded into her from behind. 

Her tits bounced with every thrust, and by the time he was done, she was leaking three thick loads and passed out right there, completely wiped out.

Once she was out cold, Yami let his real self come through, carefully carrying Angela back into their room. Quiet as a ghost, he made his way up to his father's old study, which was basically his now. 

Back when his father was around, the room was packed with books—mostly for show since the bastard had never read them. 

Yami had gone through all of them, though, keeping the 29 worth something and dumping the rest at some charity shop or burning the ones with illegal content.

He plopped down at the big wooden desk, letting out a tired sigh as he pulled out "The Grinder." 

It was a tungsten baton he'd stolen from Momo's room ages ago. Sometimes, he wondered why one end of it always seemed damp, but at this point, who cared?

Humming softly, Yami started singing a little tune Angela used to sing.

"Tatoe chiisaku te mo, tatoe bakage te ite mo…"

Then, with barely a thought, he smashed the baton into his ribs. A sharp CRACK echoed in the room as his bones shattered. 

The pain was like fire racing through his chest, but Yami barely flinched. Instead, he used petrification over his chest, feeling every bit of his bones knit back together inside his skin. 

It was sickening and painful, but there was something almost addictive about it.

And then he did it again. And again.

The baton slammed into his ribs over and over as he pushed himself further, making sure every break was worse than the last. 

His skin bruised and healed. His muscles tore and rebuilt themselves. Every nerve screamed at him to stop, but he didn't even think about quitting. 

Pain was the price of progress.

He kept singing the mantra under his breath:

"Dakedo dareka ga watashi wo dokoka de ima mo matteru…"

After two solid hours of breaking and healing himself, breaking ribs, arms, and legs, Yami finally dropped "The Grinder" onto the desk. 

His entire body shook with exhaustion, his ribs felt "funny" as if hundreds of ants were walking around them under his petrified skin, but he leaned back in his chair with a grin. 

It wasn't enough—it never was—but it would do for now.

Grabbing a textbook on fluid mechanics, Yami flipped it open and started reading. 

It wasn't casual reading, though—he devoured every word like it was the only thing that mattered. Diagrams, equations, explanations—he took it all in, his mind laser-focused on not falling behind Momo. 

She was a damn genius, and Yami wasn't about to let her leave him in the dust. 

If she reached the top, he'd be right there next to her—or ahead of her, preferably.

If she was fire, he'd be the inferno. If she reached the skies, he'd reach and take the stars.

The mantra stayed in his head as he studied:

"Kurushimi wo tokihanatsu tame, ma vie, ma vie…"

Hours passed without Yami noticing. The first light of dawn broke through the window as he finally shut the textbook and grabbed a notepad. 

'Time to work on their new training schedule.' 

He wasn't just going to plan for himself—he had Momo to think about, too. He mapped out everything: study sessions, sparring, quirk drills, the works. He left no detail unchecked.

By the time he finished, the sun was almost fully up. Yami sat back, glancing at the detailed schedule in his hands. 

It wasn't perfect, but it was enough. Stretching his sore body, he stood up, feeling every ache and bruise from his night of brutal self-training.

"Time to wake up mom," Yami muttered to himself now with a smirk, heading downstairs to start the day.