Hiro's Harem
Copyright© 2025 by Mehefin013
Chapter 4
Fan Fiction Sex Story: Chapter 4 - 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 monthly)
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
Hiro’s lunch date with Karmi was surprisingly normal. To help deal with his anxiety he decided to treat this simply as a meal with a friend, doing the same things he would probably do with Honey Lemon, GoGo, or Megan, like opening the door for her or complimenting her outfit, both of which she greatly appreciated. Since the two of them had spent much of the previous afternoon catching up with each other, their conversation today focused mainly on how to get Karmi up to speed with her robotics class. She noticeably did not mention Megan so Hiro did the same, thinking that for now it was best to let sleeping dogs lie.
Before either of them was ready for it, the alarm on Karmi’s phone went off, signalling it was time to leave for her meeting with Professor Granville.
“It can’t be that time already!” Karmi said, unable to believe they had been talking for over an hour. Disappointment was plain on her face, a fact that made Hiro feel very warm inside. “I’m sorry, Hiro. Maybe I shouldn’t have picked a day when I knew I had commitments later.”
“No, it’s fine!” Hiro said. “I had a great time. Besides, I have stuff to do as well.”
“Is it whatever you were going to do yesterday before you found your lab being suddenly remodeled?” Karmi asked, feeling just a little guilty.
“Yeah, but don’t worry about it,” he said. “It’s just a personal project and doesn’t have a due date or anything so pushing it back a day because I ended up helping a friend is no loss at all,” he said. “I’ll be honest with you. When Professor Granville told me I was getting a lab mate I wasn’t thrilled with the idea, but considering who my partner is I couldn’t be happier. I look forward to working with you.”
“Me too,” Karmi said as they both stood. Like yesterday, they were a little unsure of how to say goodbye, but this time Karmi took the initiative and gave Hiro a friendly hug, which he returned after a moment of surprise. “Thank you for letting me treat you to lunch today,” she said, releasing him. “We’ll have to do it again some time.”
“Yeah,” Hiro agreed. “Though next time I’ll get the bill. But you better get going. I know from personal experience that Professor Granville doesn’t tolerate being late.”
Karmi gave a little squeak in alarm and grabbed her purse before quickly walking to the door. “See you in class tomorrow!” she said, waving farewell.
Hiro waved back, smiling. Once Karmi was out the door he let out a sigh of relief, letting go of the nervousness he had been holding on to. He couldn’t have asked for a better first date with her, if it could be classified as one. Karmi had never actually used the word ‘date’, nor did she bring up the idea of them going steady, of course. He took a minute to throw out their trash and then hoisted his backpack and began to make his way towards the lab.
He hadn’t even made it a full block when some motion caught his eye from the nearby alley. With a second look, he swore he saw a blur of familiar reddish orange hair disappear behind a dumpster. Sighing, he crossed the street and headed into the alley. Sure enough, hiding behind the dumpster was not only Honey Lemon, but Fred and Mini-max as well. “What are you guys doing?” he asked, though the answer was fairly obvious.
“Oh, hey Hiro!” Homely Lemon said, nervousness evident in her voice. “What a coincidence meeting you here.”
“Uh, we’re just on patrol,” Fred said.
“It was not mere coincidence, nor were we on patrol!” Mini-max said proudly. The little robot was programmed with a strong sense of justice, which led to him always being honest, even when he probably shouldn’t be. Honey Lemon blushed and grabbed him and tried to stop him from talking by putting a hand over his voice box. That did nothing to prevent his speaker from working, of course, and he simply continued talking. “We were here observing your date with Karmi.”
“You were spying on me?” Hiro said, only half in disbelief. “How did you even know I was here?”
While Honey Lemon and Fred were both silent from embarrassment, Mini-max, who had no concept of shame or discretion, happily answered. “Approximately one hour and three minutes ago Megan texted Honey Lemon and informed her of your rendezvous with Karmi.”
‘Of course she did,’ Hiro thought. ‘At least she waited until after Karmi and I met up.’
“The three of us were at Headquarters at the time and Honey Lemon used Base-max’s scanning to locate you,” Mini-max explained. “She insisted on seeing in person if, quote, ‘Hiromi was real’, though I am unsure what she meant as that word does not exist in my database.” Hiro gave Honey Lemon the meanest glare he could muster, which honestly wasn’t all that intimidating.
Honey Lemon at least had the good graces to blush further. “We just wanted to make sure you were doing okay,” she said, “I mean, with what happened with Trina, and then you moving in with Megan, and now Karmi’s sudden return, there’s a lot of stuff going on in your life right now.”
While Hiro did believe that their worry for him was genuine, he was also certain that Honey Lemon’s curiosity about his love life was the real reason for their spying. “Thank you for your concern, but I’m fine,” he said flatly. “And I’d really appreciate it if you wouldn’t spy on me. My private life is not some TV show for you to watch for your own entertainment.”
“It’s not,” Honey Lemon agreed. “I know it’s not. I’m sorry Hiro,” she said, bowing in apology.
“But what if it was?” Fred added, somewhat cryptically. “What if your life was a TV show and someone was watching us right now?” He then stared down the alley, apparently looking at something.
After a moment Hiro leaned in toward Fred and looked in the same direction. Seeing nothing, he asked, “Uh, Fred? What are you doing?”
“Breaking the fourth wall, obviously,” Fred replied, walking towards the end of the alley. He stopped part way and acted as though he was up against a wall and was trying to see inside something. “If this were a TV show then the camera would have to be located right here and we’d be staring directly at the audience.”
“ ... Uh huh,” Hiro said slowly, not quite getting it but wanted to humour his nerdy friend.
“I detect no such wall,” Mini-max declared, “though there are walls to either side of us.”
Honey Lemon leaned in and joined the boys as they stared at nothingness. She decided to play along for a moment and waved at their pretend audience. “Hi everyone!” she said cheerfully. “I hope you’re enjoying the show! But if you don’t mind, we’re going to go back to our earlier conversation now.”
The four of them stopped staring down the alley and turned back to face each other. Honey Lemon bowed again in apology. “We’re sorry about spying, Hiro. It won’t happen again. It’s just ... you’re Tadashi’s little brother, and you’re a good friend, so I just want to make sure you’re taken care of.”
While Hiro appreciated his friend looking out for him, he felt this was going a step too far. “Look, I know I’m still a teenager, but I’m not some little kid that needs to be taken care of,” he explained. “We’ve all faced life and death situations dozens of times now. I can look after myself.”
“But fighting bad guys and having a romantic relationship are two very different things.”
“You are awesome at kicking bad guy butt!” Mini-max interjected, to which Fred nodded in agreement.
Hiro sighed. “I’ll admit I don’t have much experience with girls. But Aunt Cass already mothers me far too much. I don’t need or want you guys doing it too.”
Honey Lemon gave a bit of a pout. “But how will I know if you need help? We ladies are rather complicated, you know.”
“Then if I’m ever stuck on what to do I’ll ask you for advice, okay?”
“If it’s advice you want,” Fred said, perking up, “I can show you this thing I do with Olivia that makes her-”
“Fred!” Honey Lemon shouted. She slapped her hands protectively over Hiro’s ears to try and prevent him from hearing what Fred said next, though Hiro was fairly certain he heard the word ‘tongue’ in there somewhere. “Inappropriate! Hiro is way too young to be doing anything like that.”
“No I’m not!” Hiro protested, instantly reacting to being called too young as he batted Honey Lemon’s hands away. The look of surprise and curiosity she gave him made him think that maybe he had overreached. Now that he thought about it, whatever ‘that’ was, was obviously something lovers did in bed together. He couldn’t help but blush, but he also wasn’t about to back down and have them think he really was just a kid. “Well ... I’m not,” he continued, though far less aggressive compared to a moment ago. He hadn’t even kissed a girl yet, so anything beyond that was still a far off mystery in his mind. However, whatever it was that Fred was trying to say did have his interest peaked. If there was something he could do that Karmi would really like, then he’d definitely want to know about it.
After a few more apologies they parted ways, Hiro off to his lab at SFIT and the others back to HQ. Without any more surprise interruptions, Hiro was finally able to work on Trina’s cube. It was a slow process as he didn’t have a clue as to what it did or how it worked. There were dozens, if not hundreds, of points of contact that he had disconnected from her damaged skull and he had no idea which of them were inputs or outputs, or which delivered power, or even if power was needed. By the time he had to call it a day he only managed to determine what a few of those ports were not.
“This is gonna take a while,” he sighed, mentally exhausted. “But don’t worry, Trina. I’m not going to give up on you.”
Now that Baymax had been fully repaired Hiro brought his charging station to his new bedroom, and instructed the robot to assist Cass with whatever she needed when he wasn’t wandering the town observing and helping random people. Contrary to what some might believe, Hiro and Baymax did not spend all their time together, or even most of their time, as Hiro still had classes to attend and Baymax was too much of a distraction to both Hiro and the other students if the robot followed him around campus like a puppy.
As the new school week began, those living at the Cruz residence began to develop some new morning routines. While Diego and Cass could easily share the attached bathroom in the master bedroom, or even use it simultaneously, the teens had to be a little more careful in their shared use of the other bathroom. Hiro asked to use the bathroom before Megan, that way he could be done with getting ready for the day and off to SFIT before Megan was finished with her own shower, thus eliminating the chance of a repeat of Saturday. It wasn’t that he didn’t want a repeat of that event, the problem was that he did. Megan was a friend and he didn’t want to be tempted to ogle her, especially now that Karmi was back in his life. At first Megan wasn’t thrilled with the idea of using the bathroom after a boy, but when it was pointed out that he had to leave earlier than she did for class and that she wouldn’t have to rush in order to give him enough time, she quickly warmed up to the idea.
Cass took over the job of preparing breakfast for them all, which was always delicious if a little exotic from time to time, and the teens were tasked with tidying up the dishes since Cass and Diego had to leave for work much earlier than they had to leave for school. Diego would drive Cass to either the insurance agency, the Luck Cat, or wherever else she needed to be on any particular day before heading to the police headquarters himself, while Hiro and Megan would rely on public transit or personal scooters to get where they needed to go.
For Hiro, that first Monday was fairly normal save for the fact that Karmi was now in his robotics class and when the professor asked her where she would like to sit she chose the empty seat next to him. That got the two of them some friendly teasing from classmates as it was a well known fact across the campus that not so long ago the two resident geniuses could barely stand one another. Hiro also got a fair bit of sympathy from those who had heard what happened to his home.
The following day after class Hiro was tutoring Karmi in their lab on some material she was still behind on when Megan came knocking on the door, asking to speak with the other girl. Hiro gave Megan a subtle questioning look, wondering if she was here for her promised apology, to which Megan nodded in confirmation. “I’m going to go stretch my legs,” he said and got up to leave, wanting to give the two of them some privacy. “I think I’ll head down to the caf and pick something up. I should be back in a few minutes.”
“Oh. Okay,” Karmi said. It was clear she was a little hesitant to be alone with this other girl, still essentially a stranger to her, and one who was not in her good graces at the moment, but she knew something was up and was willing to hear her out.
Hiro didn’t know how long Megan would need for her apology so took his time walking down to the cafeteria. He hoped that the girls’ conversation would go well but decided a peace offering would not be out of order and bought three smoothies, one each of the classic three flavours of chocolate, vanilla, and strawberry. Upon his return to the lab he listened outside the door and thankfully heard the sound of giggling. Sighing in relief, he headed on in.
“Hey, I’m back,” he announced. “And I brought treats.”
The girls broke off from whatever they were giggling about and looked at him. “Nice!” Megan said, eyeing the smoothies.
“I’m honestly not sure what you two prefer so I got three different kinds. I hope that’s okay.”
Megan began to reach for one but stopped herself immediately. “Go ahead Karmi, pick whichever you’d like.”
“No, you can go first,” Karmi replied.
“No, please, you first,” Megan insisted. “I’m the one interrupting your time after all, and I do owe you for what I did when we first met.”
Hiro was afraid this might happen, where each of the girls would try to outdo the other in politeness by insisting the other go first, which would ultimately lead to anger for not accepting the other’s graciousness.
Thankfully, Karmi nodded in acceptance. “Okay then. I’ll have strawberry.”
“And I’ll have chocolate, unless you want that one, Hiro?” Megan said.
“I’m good either way,” Hiro said, handing Karmi the strawberry smoothie and then giving Megan the chocolate one, keeping vanilla for himself.
The three teens chatted about nothing in particular while enjoying their smoothies but the conversation eventually moved to what brought Megan here in the first place.
“So ... you two seemed to be getting along when I got back. Are things okay between you now?” Hiro asked.
“Yeah, water under the bridge,” Karmi said, “I now understand what Megan did, and why, and have forgiven her. Though she’ll be in real trouble if she tries something like that again.” The grin she had on while looking at Megan made it clear she wasn’t being serious. At least, not entirely.
“I know, I know,” Megan replied playfully. “No more implying there’s a relationship when there isn’t one. The reverse, on the other hand...” she said, giggling. Karmi joined in and the two of them sounded the exact same as earlier, making Hiro wonder if that was what the two of them were laughing about when he had returned.
A few more minutes passed before Megan got up to leave. “Well, I have to get going,” she said. “Dad’s working late so it’s my job to make supper.”
“What about my aunt?” Hiro asked.
“We haven’t had a chance to talk about it yet but if she’s not busy and wants to help out I wouldn’t say no. I’ve never had to prepare a meal by myself for more than just my dad and me so some help from someone who cooks for a living would be nice. Are you going to be eating with us, Hiro, or are you staying late to get some more work done?” she asked, sparing a glance over at the dark cube that was placed on the centre of his workstation attached to all kinds of equipment she couldn’t begin to guess the purpose of.
Hiro had made some more progress with Trina’s cube over his lunch break, eliminating further possibilities and narrowing down one particular node to only a handful of options, so figured it would be best to take a break for today. He nodded. “Yeah, I’ll be there. A word of warning, though,” he said, attempting to alleviate any nervousness she might be feeling. “If Aunt Cass does end up helping you, don’t let her experiment,” he said with a grin.
“Really?” asked Karmi. “I’ve eaten at the Lucky Cat several times and her food always tastes great.”
Hiro held up a hand defensively. “Don’t get me wrong, she is a great chef. But for every dish that makes it to the menu I’ve had to be the guinea pig for about half a dozen others that would make even Fred lose his lunch, and he eats anything.”
“So, stick to the recipe. I can do that,” Megan said in acknowledgement. “I’ll see you at home, Hiro, and Karmi, it was nice talking with you. And don’t forget what I told you, okay?” she added as she left.
Karmi’s cheeks noticeably coloured. “I won’t!” she replied as Megan disappeared into the hall.
Now that they were alone again, Hiro couldn’t resist asking. “What are you not supposed to forget about?”
“Nothing!” Karmi quickly said, her cheeks reddening even further. “It’s just girl talk. Now, getting back to what you were telling me about the laws of robotics?” she asked, evading the question.
An hour later Karmi was at her limit for absorbing new information. “Ugh,” she groaned, rubbing her temples. “I think I’m done. If we try to put one more fact in here it’s just going to shove something else out.”
“Yeah, let’s call it quits for today,” Hiro agreed, eyeing the wall clock. “Too much studying isn’t actually helpful. Sleep on it and we can do some review and maybe some practical application tomorrow. Plus I need to be home soon or they’re going to start eating without me.”
As they tidied up, Karmi placed her hand on top of Hiro’s, causing him to get goosebumps and freeze in place. “Hiro?” she said softly. “Let me first say that I’m very thankful that you’re helping me out with all this.”
“I-it’s nothing,” Hiro replied, trying to keep his voice steady. It both thrilled and annoyed him that something as simple as a touch on his hand could cause such a reaction.
Karmi shook her head. “No, it’s not nothing. I selfishly decided to learn robotics because of someone I admire.” They both knew she was talking about Hiro, but she couldn’t quite bring herself to admit it openly. “And because of that I’ve now taken over half your lab space and am stealing a bunch of your free time.”
“You can’t steal something that’s freely given.”
“Then that’s just one more reason why I need to show you how grateful I am, and treating you to a meal isn’t nearly enough of a thanks for everything you’ve done for me.” She tightened her grip on his hand as she remembered the terrible things Sycorax had put her through. “Don’t think I didn’t notice when you immediately put yourself between me and Knox when we got locked down in sub-level 9. And I shouldn’t even have to mention how you saved me from Diane when she...” Being transformed into a literal monster was not something Karmi liked to remember.
Hiro gave her hand a comforting squeeze back. “Did you forget that you saved me too? When you were transformed you not only resisted Diane’s orders but actually fought that hulked out Chris in order to protect me.”
“I didn’t forget, but my memories when I was ... not myself are kind of hazy ... And honestly, I’d rather not remember what she made me do.” Karmi admitted. Thinking about how her body had been mutated and how she had almost no control over her own thoughts, let alone her actions, made her skin crawl. What happened to her would not be classified as rape since there was no sexual component to it, but she had definitely been violated. “But if it wasn’t for you always helping me and being nice to me, even when I knew you hated me-”
“I never hated you,” Hiro interrupted. Karmi responded with a look of obvious skepticism. “It’s true that when we first met I found you, um, hard to get along with,” he said, being careful with his words. “But I never felt anything even close to hatred.” Saying that he used to find her irritating, insufferable, or that he could barely stand being in the same room as her, while true, would definitely be unwise. Then there was her crush on his superhero identity while actively disdaining his civilian one, which just made things really weird and awkward.