Hiro's Harem
Copyright© 2025 by Mehefin013
Chapter 9
Fan Fiction Sex Story: Chapter 9 - Hiro may be the youngest person to ever attend SFIT, but that doesn’t mean he’s too young to handle the various challenges that come with college life, including love. But what will he do when that particular challenge comes from several different sources at the same time? (Updated twice a month)
Caution: This Fan Fiction Sex Story contains strong sexual content, including Ma/Fa mt/ft Ma/ft mt/Fa Fa/Fa ft/ft Fa/ft Mult Teenagers Consensual Lesbian BiSexual Heterosexual Fan Fiction Sharing Incest Father Daughter Aunt Nephew Group Sex Harem Polygamy/Polyamory Interracial White Male White Female Hispanic Male Hispanic Female First Masturbation Oral Sex
Megan threw open the front door of her house before Hiro had even reached it. She stared at him, not saying anything, which caused him to blush slightly under her gaze.
“What?” he said.
“You and Karmi had sex, didn’t you?” she asked. It was almost more of a statement of fact rather than a question. Hiro’s blush immediately spread over his whole face and he couldn’t stop the small smile that appeared at the thought that yes, he did in fact have sex with Karmi. “AHA! I knew it! You totally did!” she said, jabbing a finger into his chest. “I’ve never seen a guy’s face after he’s just ... you know, but I’d imagine he’d look exactly like you.”
“Like what?”
Megan quickly pulled out her phone and snapped a picture, then showed it to him. “Like this. This is definitely the face of a guy who just had the best sex of his life.” In the picture, Hiro wore a goofy lopsided grin that practically screamed that he’d just gotten laid.
There was really no point in denying it. If Hiro didn’t confess then Megan would definitely get what she wanted out of Karmi sooner or later. Probably sooner. “Does it still count as the best if it’s the only sex you’ve ever had?” he said in answer.
Megan’s eyes sparkled in excitement at his admission. “Definitely! Although if I had to guess, it still would have been the best even if you’d been with like a dozen different girls before.”
“Ha! Like that would ever happen. I’m lucky enough to get the one, and I plan on keeping her as happy as I can. Plus I don’t think any girl would be very happy to learn that she was number thirteen in a long line of conquests. Now are you going to let me in or is this interrogation going to keep going?”
Megan smiled and stepped to the side, allowing him in. “Don’t think this conversation is over. I’ve got lots of questions, for both you and Karmi,” she said. “But I imagine you could use a good night’s rest, even if you probably spent most of the day in bed,” she added with a wink.
Hiro only made it as far as the living room before he was stopped again. Aunt Cass was waiting for him on the couch and motioned for him to sit down. “So, how did things go with Karmi?” she asked.
Hiro tried his best to act normal. The last thing he wanted right now was for his aunt to learn that he just lost his virginity. “Um, fine.”
Cass arched an eyebrow at him. “Fine? Just fine? How did she react when you told her you were in Big Hero 6?”
“Oh! Right! She, um, she took it pretty well, all things considered.”
“She totally fucked his brains out,” Megan added with grin as she leaned on a nearby chair. Hiro let out an exasperated sigh. So much for that idea.
“Megan, language!” her father reprimanded from the kitchen where he was drying the last of their dishes from supper.
“Sorry Dad,” she replied, rolling her eyes.
“And don’t roll your eyes at me,” he added, even though he couldn’t possibly see that from his position.
“Is it true?” Cass asked Hiro, her own face a little red now.
“Is what true?” he said in a last ditch effort to avoid the topic.
“Did you and Karmi ... have relations?”
Hiro really didn’t feel comfortable talking about this with his aunt, especially with the Cruzes being right there, but he wasn’t going to deny it. “Considering that’s rather private information, I don’t see why it should be any of your business, but yes, we did. And before you ask, yes, she’s protected. And that’s all I’ll say on the matter.”
Cass looked at him as if she was trying to see any sign of his lost virginity. “Okay,” she said, her voice a little shaky with emotion. “I knew this day would come sooner or later. I was encouraging you to date after all, and dating often leads to ... sex. I guess my little man isn’t so little any more.”
“But he definitely is a man now,” Megan said.
“Megan, you’re not helping,” Hiro said, giving her a stern look. Or tried to, at least. The smile she returned showed she wasn’t bothered in the least.
“You know, I still haven’t met this girl, and now she’s taken my boy’s virtue. When do I get to meet her?” Cass asked, but then kept talking without giving Hiro a chance to answer. “Is she pretty? What am I saying? That sounds rather vain. Who cares if she’s pretty or not. Then again, you did show me a picture of her so I already knew she was pretty. Is she nice? Of course she’s nice, otherwise you wouldn’t have-”
“Aunt Cass?” Hiro said, interrupting her.
“Hmm?”
“You’re rambling.”
“ ... Sorry. It’s just, this is a lot to take in.”
“I’m still the same person I was this morning, you know. Did you react this way when you learned Tadashi was ... active?”
“No. Wait, back up there. Your brother was having sex!?” Aunt Cass asked, completely shocked.
“You mean you didn’t know?”
Cass shook her head. “No. I mean, he was in college and the ladies all seemed to like him, for obvious reasons, so it would kind of make sense that he was, but he never had any overnight guests and there weren’t any signs that I could see that said he was actually sleeping with any of them.”
“Well, if SOMEONE hadn’t just blurted it out,” Hiro said, sending another glare towards Megan, “then I would have been the same. Until I was actually ready to tell you, at least. Anyway, to go back to your original question, Karmi was happy to learn I am part of Big Hero 6, and she will definitely keep it a secret.”
Hiro then had to spend the next hour going over all the various details that Cass asked about, and even a few from Diego; what Karmi was like, how they met, how big of an age gap there was (that was Diego’s question, as he wondered at the legality of the relationship given Hiro’s status as a minor), how they got past their initial antagonistic relationship, what Hiro felt when she suddenly had to leave, how the two of them managed to reconnect after so many months apart, and many more questions besides. It was a long and tiring process after a long and tiring day, and when Hiro was finally able to escape to his room he did so with very tired steps.
Unfortunately for him, Megan wasn’t quite done. She followed him down the hall towards their rooms, ostensibly to turn in for the night herself. “I have to admit, I’m a little jealous,” she said once they were out of earshot of the adults.
“Jealous?”
“Yeah. While your aunt was giving you the nth degree I was texting with Karmi. Seems you did a really good job. She told me her first time was absolutely perfect. Makes me wonder when I’ll get my turn.”
Hiro nearly ran right into his door, caught off guard by Megan’s words. “Whoa, whoa, whoa!” he said, careful not to raise his voice too much so the adults would hear. “Your turn? You do know that me dating Karmi means I’m not available, right?” Surely she was just teasing him, but this was perhaps going a bit too far.
Megan gave him a sly grin. “Who said anything about you? Geez, a guy has sex one time and all of a sudden he thinks every girl he knows wants to sleep with him or something.” Contrasting Hiro’s face which was as red as a tomato, she was as cool as a cucumber.
“But you just...!” Hiro began, carefully recalling what Megan had just said. “Well, you might not have said ‘me’ specifically, but you certainly implied it! I mean, who else would you be talking about?”
“Oh? Getting jealous, are you? Even though you already have Karmi you want to keep me all to yourself, too?”
“That’s not what I ... You know what, forget it. I’m too tired to play this game right now. I’m not your brother, I’m not your dad, I’m not your boyfriend. If you want to have sex with someone else, then fine. It’s not like I’ve got a claim on you or anything.” Even though everything he just said was technically true, Hiro felt like it was still a lie somehow. Megan was his friend and even if it did come across as jealousy, the thought of her getting it on with some random guy made his stomach churn. “Just ... don’t go doing it simply for the sake of doing it, okay?” he said with complete sincerity. “I can say from personal experience that it’s worth the wait to do it with someone you truly care about.”
Unexpectedly, Megan darted in and gave Hiro a hug. “I know,” she said, letting go and backing away almost immediately. “Thanks for looking out for me.” She could hear the sincerity in Hiro’s words and genuinely appreciated them.
“While I may not be your brother, your dad, or your boyfriend, I am still your friend. And a superhero. So long as it’s within my power, I will protect you from any threat, be it a supervillain or some douchebag guy trying to take advantage of you.”
“Noted, though I’m pretty sure I can handle any douchebags on my own. My dad made sure of that.” Demonstrating, Megan made a series of quick fighting maneuvers towards some very sensitive locations on Hiro, though she stopped before actually connecting. “And if that fails, I’ve got bear spray, a taser, and a panic button that links directly to the police HQ. Being the chief’s daughter does come with some perks, after all.”
Hiro gave a little chuckle. “That’s good to know. But I really am exhausted and need to go to bed. Goodnight, Megan.”
“Goodnight, Hiro,” she said, and they both headed off to their own rooms.
Hiro was so tired that he didn’t bother changing into pajamas but just stripped down to his underwear and climbed into bed. He was asleep seconds after his head hit the pillow.
The following day Hiro was awoken by the sound of his phone receiving a text message. It was from Karmi and read, “Thank you again for yesterday but I woke up even more sore than when I went to bed. It’s a good sore, mind you. Makes me giddy whenever I think about why. But I think I’m going to take it easy and just soak in my tub and chill in bed all day long.”
It made Hiro happy thinking about it as well. His usual morning wood shifted from just hard to hard with a purpose in mind. “I’m sorry to hear that,” he texted back. “Where exactly are you sore?”
“Don’t be sorry, and you know exactly where, you beast! 😜” Karmi replied.
Feeling a little bold, Hiro texted, “No, I don’t. Why don’t you show me?”
“You’d like that, wouldn’t you?”
“Of course I would.”
It took a lot longer than expected before Karmi replied. “Just to make sure, you are alone right now, right?”
‘Oh my god!’ Hiro thought. ‘Is she actually going to do what I think she is?’ “I am,” he replied.
Another minute passed before the next message came. “You’re lucky I’m such a considerate girlfriend,” Karmi said. Following her message was an image, and Hiro’s heart nearly skipped a beat. There was Karmi, lying on her back while taking a selfie that showed almost her entire body in a large mirror. Her legs were spread wide open and she was completely naked, with her vagina being unashamedly displayed front and centre.
“Was this what you wanted to see?” she asked.
Hiro gulped. With hands trembling in excitement he managed to carefully type out his next message. “Mind if I come over? I could kiss it and make it all better.”
“LOL! Thanks, but no. And believe me when I say how hard it is for me to say no. But you need to stay away from me for at least twenty four hours so that I can recover properly.”
“What if I send Baymax over to you? He could make sure you get exactly what you need to recover as fast as possible.”
“No offence to Baymax, but I’d rather not have anyone tend to me just now, robot or not. I’d just like some quiet me-time today. I’m sure I’ll be good to go before long.”
Hiro was naturally disappointed. He could hardly wait to be with Karmi again, but he wasn’t going to push when he knew it would only be a matter of time before they would be together again. “Okay, I understand.”
Hiro thought their conversation was over with that, but saw that Karmi was still texting. It took multiple posts but she eventually said, “So ... I was wondering ... since I just gave you a pic of me ... how would you feel about sending me one of you?”
Hiro had never taken a naked selfie before, but that didn’t stop him from practically jumping out of the bed and dropping his underwear. Not letting himself think too much about it to avoid getting cold feet, he took just a few seconds to get a good angle to make his erection look as big as possible, then snapped a picture of himself and hit send.
“Very nice! Now I’m kind of regretting not letting you come by,” Karmi replied. “Eager for more, are you?”
“Can you blame me? I was already hard just thinking about yesterday, but after the pic you sent I’d have to be dead to not be like this!”
“Well, I might be out of commission for today but don’t let that stop you from having some fun yourself. But not too much fun. I want you to be in top form for when I am fully recovered.”
“Yes, ma’am!”
They said their farewells and with the conversation finished Hiro quickly went about doing just as Karmi suggested. He came once before even leaving his room and once again in the shower before his hard-on finally showed signs of weakening. The two naughty pictures he had of Karmi plus the very fresh memory of their first time together was more than enough fuel to keep his fire burning hot even after he reached climax. He probably could have kept going but spending so much time in his room and the bathroom was bound to draw unwanted attention sooner or later, not to mention his dick was starting to get sore from receiving so much action in such a short amount of time.
With his girlfriend essentially banning him for the day and him being all caught up with his schoolwork, it was the perfect opportunity for Hiro to spend the entire day working on Trina’s cube. That would be a good use of his time as well so he wasn’t wasting hours just fantasizing what he would do with Karmi once they were together again.
He made his way to campus and sat down to work. With all the things he had figured out wouldn’t work, he was bound to find something that would, and today was going to be that day. As morning became afternoon and afternoon became evening, still with no success, Hiro was starting to lose motivation. He had tried every node he could find, testing it for any sign of power, or if he could send a signal into it or get a signal out of it. He was being extremely cautious as any accidental power surge could potentially destroy whatever was inside, thus ensuring Trina’s complete destruction. With nothing left to think of, he decided he’d have to take a risk.
He attached sensors to every node simultaneously, making the cube look somewhat like a boxy porcupine, and connected the shell of the cube itself directly to a source of power where he could control exactly how much electricity was transferred. He had to take a gamble at how much voltage Trina would have used, but considering she was a robot capable of interfacing with everyday computers he decided to go with the standard 120 volts. Starting small, with just a single milliamp, he slowly increased the amperage every thirty seconds and monitored the nodes to see if there was any reaction, with the system designed to stop the increase if there was any activity detected in any of the nodes. With nothing detected in the first hour, Hiro was again beginning to lose hope of ever being able to access whatever was inside that cube.
Suddenly, when the power reached 167 milliamps, half of the nodes lit up with activity! Hiro nearly fell out of his chain in surprise as signals started pouring in from dozens of sensors. The data made no sense, but that was to be expected since Trina would have had a completely different operating language compared to Hiro’s lab equipment. It was all just garbled nonsense on his screen, like opening up an image file using a word processor and getting what looked like random letters and symbols everywhere. But still, hope bloomed in his chest. There was something in there after all. He would need the right program to decipher the data, either by salvaging something from Obake’s lair that was still usable, or reverse-engineering it himself. The former was ideal as creating something from scratch could potentially take years depending on how complex this code was.
Not wanting to risk letting the cube stay active for too long Hiro cut the power and the cube went quiet once more. “That was you in there, right?” he said, looking at the dormant cube. “I will keep my promise, Trina. We’re one step closer to bringing you back.” Plans were already taking shape in his mind as he thought about what to do next.
The following day, Hiro found it incredibly difficult to concentrate in certain classes. Not because of his progress with Trina, but because Karmi was sitting right next to him. It was subtle enough that the other students either did not notice, or simply didn’t care, but the two of them were constantly holding hands or rubbing a leg against the other. Hiro tried not to imagine he and his girlfriend back in bed together, but the looks she gave him made it hard to think of anything else.
After classes were finished the two of them headed to their shared lab to work on projects. Karmi immediately noticed the cube with all the sensors attached. “This setup is different,” she noted. She had seen the cube before but knew nothing about it other than it was a personal project of Hiro’s.
“Right,” he said, more to himself than to her. “Now that you’re in the know about my, um, other hobby, I should bring you up to speed on this.”
Karmi’s eyes lit up with excitement. “Oh! Is this related to Big-” she stopped herself and looked around the room to make sure they were alone. “Is this related to Big Hero 6?” she finished asking, her voice a conspiratorial whisper.
“Sort of. You already know that the Lucky Cat was attacked, but what you might not know...” Hiro then spent the next half hour explaining the situation to Karmi. She listened intently, asking questions only rarely as Hiro detailed his history with Trina and what brought them up to their present situation.
“So your first girlfriend was a robot,” Karmi said teasingly once Hiro was finished with his tale. “Why am I not surprised?”
“She was never my girlfriend!” Hiro protested. “And technically she’s an android, not a robot.”
“Same difference,” Karmi said, waving a hand dismissively.
Before their conversation about Trina could go any further, there was a knock on their door and it opened a crack. “Hey, I’m not interrupting anything, am I?” came Megan’s voice.
“Hey Megan!” Karmi said. “No, come on in.”