This is gonna be a flashback chapter to when Izuku first started his ordeal to take down Mineta. There's going to be a few so make sure you look out for them. Enjoy.
Flashback a year ago
Anxious. That was probably the best word to describe what Izuku felt. Not even a week passed since his failed confession with Ochako and the dark reality as to why and he's already looking at probably the strangest thing he could ever imagine. His childhood friend planning to help him crush another human being in his thought process and using her own body to help with it.
'Ok Izuku. Just calm down. Kat normally jokes a little too much and she might not be saying this as a way to help me. This probably isn't anything deeper than that.'
As he thought this, Mineta walked in with Ochako beside him as he locked eyes with Izuku and gave a smirk. "Ochako. Your BJ last night was awesome. Definitely sucked me like you wanted my jizz."
"Ehehehe. Mineta. I don't think this is the place to be saying stuff like that." Ochako tried to play this off and avoid anyone saying anything about their 'relationship' with the small pervert not getting the hint.
"And your pussy felt like you wanted me to knock you up. Good thing we had condoms on or you'd be loaded with baby batter today." He kept going on with it feeling like needles going in Izuku's ears for him to hold his head on his desk. This just made Izuku feel more like he wanted to curl up in a ball and die somewhere only for Katsumi's words to continue to echo in his mind.
'I know he's terrible. I know he's the worst person for her to be with. But maybe that rumor was wrong-'
"MINETA! SEASE YOUR DISRESPECTFUL ANTICS IN CLASS THIS INSTANT!" Iida shouted for Izuku to look up and see Mineta's hand up Ochako's skirt. The moral disgust was obvious on her face as the brunette caught a glimpse of Izuku. She began biting her lip in frustration before moving out of Mineta's reach.
"I-I'm not feeling so well. Iida, do you mind telling Mr. Aizawa I had to use the restroom for a little bit?"
Iida glanced at his friend to understand she just wanted to get away for the moment before nodding. "Try not to stay in the restroom too long into class."
"I won't." Ochako practically ran out with Izuku seeing out a glance a tear starting to come up in here right eye.
At this point, Izuku didn't care if it was mean. All he wanted was the person he cared for to stop being put through this. 'This asshole's going down.'
Later that afternoon
Laying on his bed, Izuku tried to think through if he genuinely wanted to go through the exact route. Unfortunately if the rumor Nejire told him was true, there's nothing he could actually do without one of the girls speaking up against him. But the second they do, they could get hit with the worst outcome of whatever dirty laundry they're hiding being let out for everyone to see. "Is this really the only route to help everyone?"
Thinking back to yesterday, Izuku went in his drawer to grab the underwear Katsumi gave him. He glanced at it and noticed something off. 'Is that a little bear on the back?' He found it a little cute before slowly bringing it to his nose. 'This is only because of helping Uraraka and everyone. I'm not some kind of pervert.' Before he could, his phone went off to make Izuku jump and fall off his bed. "Ow." He grabbed his phone on the side and picked it up. "Hello?"
"Hey, Izuku. Is your mom home right now?"
The voice on the other side was Katsumi for him to blush a bit. "N-no. It's just me until later tonight."
"...Ok then. Are we still on for tonight?"
"Wait, you mean what you said yesterday?"
"Yes."
"I-I thought you were joking about that." Izuku panicked a bit with Katsumi sounding a little uneasy on the other side of the line.
"D-don't think I'd make claims like that and give you my panties for a joke, dumbass! Besides, I already made up my mind to do this. And to be honest, can you live with knowing this and looking at the girls in your class?"
"...you're right. I don't think I can."
"Good. Now I'll be there in five."
Ok." Izuku hunt up and looked at his room. There were a few things on the floor and a few cans of soda he's let accumulate in a few days. "I should probably make sure everything's clean before she gets here."
Izuku took the time to clean his room and at least make it presentable enough where he won't feel as guilty having Katsumi stay in it. Once he finished cleaning the bowls and cups and placed them on the drying rack, the doorbell rang to have Izuku head towards the front. Once he opened it, Katsumi was waiting in a sleeveless black shirt with a skull and white gym shorts. "Hey."
"Uhh, hey." The two stayed silent for a bit before Katsumi cleared her throat to give Izuku the message to try and break the ice a bit. "C-come in." They walked in and went towards the couch. The two sat in what felt like an eternity. Both were somewhat uneasy on how to start this.
"So umm...you wanna...do something to break the ice first?"
"Like what?"
"Well." Katsumi put her fingers together before answering. "We could umm...k-kiss first and go from there." Hearing this, Izuku went red before looking at Katsumi. She seemed to be just as red while trying to avoid the embarrassment of what was happening. He knew he had to act first to avoid making his childhood friend from feeling anymore unease.
"Ok." He gathered up all the courage he had and turned towards Katsumi. He placed his hands on her shoulders before slowly moving to kiss Katsumi. She was uneasy with this not being the type to let someone take the lead, but knowing Izuku needed to make the first move before her. As their lips met, Izuku took note of how soft Katsumi's lips were as her hands started to move to his chest.
As this occurred, Katsumi began to fall into the feeling of this and moved a bit forward. 'This feels nice. I...I think I like kissing.' Her arms started to wrap around Izuku's neck as his slid down towards her back. In the heat of the moment, Izuku didn't acknowledge him falling backwards on the couch to fall to his back and have Katsumi land on his chest to feel her chest press against him. The soft sensation forced his mind to go into overdrive and begin to react. "Hmm?" Katsumi pulled herself away as she felt a tent start bulging in Izuku's pants. She smirked seeing this before looking down at Izuku. "You wanna take this in the other room?"
Izuku nodded slightly as they got up and began heading towards his bedroom. Katsumi shut and locked the door behind them before walking over and giving Izuku one more kiss before pushing him back to sit on the edge of his bed. When he did, the ash blond latched onto the sides of his shorts and boxers with a little nervousness. She decided to go all at once in order to prevent anymore dragging in her belief. Once she did, she saw Izuku's semi flaccid member stand up.
"Holy crap, Izuku. It's bigger than I remember." She went down towards his lower half to take a bit more of a closer look. 'So this is what a man looks like when he's interested in a woman sexually.' She started to slowly move her hand to grab Izuku's length and slowly move it up and down. 'When I saw Katsuki do this to himself, he seemed to enjoy it. So does that mean guys like this?' The ash blond thought back to the few times she's seen her brother handle himself to remember him watching a dirty video in his room. 'If I remember, the woman took the dick in her mouth like this.' Katsumi opened her mouth to put the head of Izuku's dick in her mouth. The soft sensation of her tongue and mouth forced Izuku to stifle a moan. 'This kinda hurts to do. I think she tried to put it deeper in.' She continued to go as deep as she could to gag at almost the halfway mark. The act made her throat tighten and have the OFA user get shivers down his spine.
Katsumi continued to try to get Izuku's member deeper down her throat with her mouth feeling Izuku's dick become harder. "I-Kat. I-I'm gonna..." In the heat of the moment. Izuku grabbed Katsumi's head and slammed her down to have her throat clogged before feeling Izuku shoot his semen down to her stomach. During the act though, some of his cum dripped off and onto her shirt. Once he finally finished, Izuku let go of Katsumi's head for her to pull away to get air and cough out some of Izuku's seed. "Sorry."
"*cough* *cough* Give a little warning next time. Felt like I was gonna suffocate or drown."
"Sorry. It just felt too good."
Katsumi calmed her breathing down enough to be a bit more relaxed. As she did, she started to taste Izuku's semen to notice something off. "Weird. It tastes sweet."
"Umm...That's cause of my...quirk."
"Huh?"
Izuku started to explain. "You see, my quirk gives me a bit of body alterations. From what I was told, semen production is increased to about twice what it would be in a normal person and can go up to about eight times in a situation where I'm sexually active. Any stored nutrients in my body can be adjusted to the protein to produce more reserves. Along with this, I've been in a situation where I've needed to create a release at least once a day even while training. In addition, I was told the potency of my seed is increased with the flavor being-"
"Enough. I get it. You turned into a sex machine." Glancing back at Izuku's member, Katsumi noticed it was still standing tall. "Seems you're still ready." She got up and began pulling off her pants to show a black pair of underwear. Adding to this, she pulled her shirt off to show a similar bra.
"W-wait. Why are you pulling off your top too!?"
"It's not a safe day for me. I didn't have a fucking clue about the size condom to buy and didn't wanna waste money on something I might not be able to use and if what you say is right, you'd probably get me pregnant if you finished inside me. So I'm making it so I can at least wear everything but my shirt home and borrow one of yours." She pushed Izuku on his back and went on top, aligning her entrance with the tip of his dick. She glanced down at the size with some worry. 'Will this fit?'
Izuku glanced up at Katsumi with her slender body in full view. He took note of her breasts which were roughly about average size with her body's skin practically glistening. 'I...I never realized how feminine Kat looks.' He blushed while his dick began to throb a little.
"DON'T STARE AT ME LIKE A FREAK RIGHT NOW! I'M TRYING TO SHOVE YOUR DICK IN ME, THE LEAST YOU COULD DO IS NOT LOOK AT ME LIKE I'M SOME KIND OF EYE CANDY!"
"S-sorry. You...just looked very womanly I...I couldn't help it." Hearing this, Katsumi blushed before scowling a bit.
"Whatever. You wanna see how much of a woman I am, then here you GO!" She slammed Izuku's dick into her pussy full force with it reaching all the way up into her womb. The act stiffened her body up as she froze where she was.
"Kat. You ok?"
"J-just give me a minute." She tried to wait for a moment with Izuku's body subconsciously moving his hips. "I said give me a minute!"
"Sorry. I can't stop my hips. Your insides feel too good." Izuku moved his hands to hold onto Katsumi's hips as he lifted her up. The act gave her a bit of relief before Izuku pulled her to only have his tip in her before dropping her back on his lap, sending his member back all the way to her cervix. This forced Katsumi's body to fall forwards on Izuku with her eyes rolled in the back of her head.
"You huge bastard. If you're gonna fuck me on your own, then put me in a spot that I can at least enjoy it better."
"R-right." Izuku moved Katsumi while still inside her to place her on her back and be on top of her. Once she was in a more relaxed spot, Izuku continued to thrust inside her. The pain she initially felt calmed down and gave now overwhelming pleasure. Her inner walls wrapped around Izuku with his member feeling every curve and bump inside her as they slowly altered and changed to fit the OFA user's length. While this happened, Katsumi wrapped her legs around Izuku and held onto his neck. Kissing him in the process while rubbing her nipples against Izuku's chest.
As they continued, Izuku's dick began to bulge up in Katsumi's body for her to be in her own little world. 'Oh my god. Please don't let this stop. I don't care what I need to do, just please let me have this dick for longer!'
"Kat. I'm gonna cum." Izuku's hips gained speed with Katsumi not immediately hearing and comprehending what was said for Izuku to speak up. "Katsumi! I need to pull out!"
Now coming back to reality, Katsumi let go of Izuku and tried to push him back. "You can't cum inside me no matter what!"
Izuku was able to pull out in just enough time to avoid finishing inside Katsumi. Once he did, his sperm sprayed out of his dick and coated Katsumi's face and chest. Due to the sheer amount given, the ash blond's upper body was covered in Izuku's hot seed with some pooling on her stomach that dripped out of his shaft. As the two laid there panting, Katsumi glanced down at Izuku's dick.
"You gotta be kidding me." In front of her, Izuku's member was still standing tall to surprise her. "WHAT THE FUCK IS YOUR BODY MADE OF TO GET TWO HUGE LOADS OUT AND WANT TO SHOOT A THIRD!?"
"Sorry." Izuku felt a little embarrassed before Katsumi got up and grabbed her clothes and one of Izuku's shirts from his dresser.
"Good grief. Lets go. We're going into your bathroom."
"Wait, why?"
"To get the cum off me so nobody stops me and questions why I look like I had three guys have a party with me and to mellow out your dick more."
"Wait, so we're doing it in the bathroom too!?"
"Do you want your sheets to get dirtier?" Izuku glanced back to realize he'd have to clean his blanket and anything that the semen stains on top of it sank into. "Didn't think so." As such, the two continued their acts in the bathroom. Katsumi continued to explain how to pleasure a woman while also teaching him how some parts of the body can make a woman feel more desire. Along with this, they tried different positions in which allowed Izuku to understand how women can feel different depending on how you enter. In addition, the two had tried anal with it ending in a somewhat painful and shocking experience for Katsumi. Due to the amount that was still coming out, she had looked like she was at least three months pregnant once they finished. In the end, they had spent a notable amount of time in the bath before finally finishing up and having something to eat.
Few hours later
"Starting now, we'll be fucking daily." Katsumi blankly stated with Izuku still confused. "Since your mom took a job that brings her into the night, I'll say I'm hanging out and making dinner for you so she doesn't get suspicious if I leave stuff here or return a shirt of yours."
"Ok. Sorry you have toOOOF!" Katsumi socked Izuku in the gut for him to get cut short.
"STOP FUCKING APOLOGIZING! The first thing I want to break you of is the thought that everyone wants to hear 'I'm sorry' from you. You've let shit go on with you for years and you let it go. THAT'S WHY PEOPLE THINK YOU CAN BE STEPPED ON! For you to do what you wanna do, you need to grow a spine. I'd say balls, but I don't think I'd be able to handle you if your pair grew more."
"Right. Sor-I'll work on it."
"There we go. Alright. I'm off." She started walking away before stopping. "Oh, I also wanna ask you. Gimme that blue haired girl's number."
"Wait, you mean Hado?"
"Yes I mean Hado. Gimme her number. I wanna hear everything she heard from your girlfriend and froggy. Maybe I can also get her to help out."
"Wait, why would you want her to help?"
Katsumi seemed a bit irritated before commenting. "She's got a big ass and tits to match, right? She can do things mine can't. Also, you'll need to know I'm not the generic type when you sleep with a girl. Having someone else help also helps my back. Seriously. Learn how to avoid turning me into a fucking sex doll." She held her back and walked out with Izuku still confused.
'Just what the heck happened to make this now my normal life.'
Back to the present
Izuku woke up with a warm sensation on his groin. He glanced to his side to see Mina out cold with a bloated stomach. Remembering back to the night before, he grabbed the covers and pulled them up to notice Fuyumi bouncing her ass on his pelvis. "Morning sleepyhead."
"Morning. So how long have you been at this for." Izuku shot another load into the older woman for her to hold a face of pure bliss.
"About five loads right now."
"...You did take contraceptives, right?"
"Maybe~" Izuku stared at her blankly for Fuyumi to roll her eyes. "Yes. I took birth control. I know you're a hero in training, but can you at least let me have a baby. My friends from high school are all getting kids and I want one myself."
Izuku gave Fuyumi a deadpan look before answering. "We'll talk about this later when you're off my dick."
And that finishes this chapter. So I'm going to have some flashback chapters in this more to tell the story of how Izuku got the girls in his harem. See what happens next time. Hope you all enjoyed and thanks for reading.