My Little Sister Is the Best F*p Material - Volume 4 Chapter 2: For a Beautiful Girl, Comfort is Key

Volume 4 Chapter 2: For a Beautiful Girl, Comfort is Key

After messaging Yamamoto-san to ask when we could meet, she replied that we could go on a date that very afternoon. I hurried to get ready and managed to make it to our meeting on time. Originally, Yamamoto-san and I had agreed to have sex to help each other with our personal issues, but this time was different. Despite having slept twice, I’d already ejaculated three times with Miyu this morning, so I decided to take a break today.  

“Onii-chan, you’re going out?”  

“Yamamoto-san made time for me.”  

“I see. You’re going, huh?”  

Miyu no longer bothers to hide her flat tone of voice. It’s astonishing that she claims not to like me as a man. Maybe she’s a severe case of “bra con” or something.

I understand that engaging in intimate acts with a sibling is wrong, which is why I’m striving to distance myself from Miyu. However, that’s more of a rational, brain-driven thought. My lower half would be more than happy if Miyu were a “bra con.” I want to sleep in bed with Miyu again, take baths together, and be forced to ejaculate despite her reluctant expression, all while she’s oddly proactive.

(Thinking like this is why I can’t distance myself from her…)  

Feeling this way is unfair to Yamamoto-san, who’s kindly helping me. Even though our sexual encounters are meant to solve her problems, that’s a separate issue. For now, I need to focus solely on Yamamoto-san and her needs when we’re together. That’s my duty as her brother.

“Alright, I’m off. I’ll let you know when I’ll be back.”  

I shook off my hesitation and left the house. The meeting spot was set at a nearby bus stop. While the station would have been easier to meet up at, I decided on the bus stop since Yamamoto-san mentioned she’d be taking the same bus.

When I arrived at the designated location, I spotted Yamamoto-san, wearing a hat and carrying a small white bag, waiting under the bus stop’s roof. Despite her efforts to conceal her ample chest with a modest shirt, her high-waisted skirt only drew more attention to her large breasts. Thinking about how she gave me a paizuri with those breasts made me realize how surreal my life had become.

“Sotomichi-kun, good morning. I was surprised to hear from you so suddenly.”  

“I just really wanted to see you, Yamamoto-san.”  

“Hehe, you’re the type to casually say such sweet things, huh? That’s a bit unexpected.”  

“Eh? Ah, um…!”  

I was so focused on escaping Miyu’s temptations that I didn’t consider how my words might be received. Indeed, my dialogue was rather blunt, almost like something a woman would say.

“I figured someone like Yamamoto-san would be used to hearing such things.”  

I couldn’t bring myself to say that I needed Yamamoto-san’s help because I’d been intimate with Miyu—not yet, for Miyu’s sake. Yamamoto-san is likely praised by many just for being herself, so this reason wouldn’t seem unnatural.

“That’s not true… Ah, the bus is here.”  

Yamamoto-san either brushed it off or dodged the question, pointing to a bus in the distance to divert my attention. We boarded that bus together, and since the seats were full, we held onto the nearby hand straps. Standing next to a girl around my height felt refreshing, as Miyu is nearly twenty centimeters shorter, making our eye levels align perfectly. It’s amazing that such a cute girl would agree to date me just because I contacted her. My life has completely transformed since last year.

All of this is thanks to Miyu. While our physical intimacy is only recently allowed to a limited extent, she taught me how to be popular, introduced me to girlfriends, and without her, I’d probably still be holed up in my room, watching videos on my computer.

Come to think of it, Miyu gave me a handjob this morning. While I can’t count the oral release as fellatio, the final act in the futon was clearly a handjob. The experiences in the toilet and bath might be making Miyu more comfortable with intimate acts. If so, given that she’s already placing her lips on the tip of my penis, maybe one day she’ll calmly give me fellatio too.

(No, stop it. That day will never come. I can’t let it.) 

I shook off my wandering thoughts for the umpteenth time, reminding myself that I was currently standing on a bus. We’d already decided to have lunch together, but I hadn’t thought about what to do afterward.

“Um… Yamamoto-san…”  

When I spoke up, Yamamoto-san, who had been quietly reading the in-bus advertisements next to me, glanced over briefly before turning to face me.

“What is it? You’re calling out to a girl, but your mind seems elsewhere, Sotomichi-kun.”

“Ah, sorry. I was just spacing out. I was thinking about what we should do after lunch this afternoon.”

I took out my smartphone and searched for events around the station. Instead of using her own device, Yamamoto-san leaned in to look at my screen. Her curvaceous body pressed against mine, radiating more heat than I’d expect from a single person.

I found several promising sites and scrolled through them, but Yamamoto-san remained silent. She didn’t seem bored, though—her eyes were intently fixed on the display.

“Did you find anything good?”  

When I asked her, a bit nervously, Yamamoto-san seemed to snap out of her focus and finally met my eyes.

“Oh, sorry. I was just looking at the predictive text suggestions for your… preferences.”  

“Please give me a break.”  

Yamamoto-san can be just as careless.  

“For now, since we’re almost at the station, let’s figure it out while we eat.”

Following Yamamoto-san’s lead, I got off the bus and we headed to a Western-style restaurant. Along the way, I noticed a flyer that caught my eye, and as I stopped to look at it, Yamamoto-san paused with me.

It was a flyer for a mystery-solving event. Apparently, it was being held today in a building a few stations away. The event had multiple sessions throughout the day. I’d heard about these events before and often played similar games online, so I was curious. I wonder what a real-life mystery-solving event would be like.

“Are you interested?”

“Eh? Yeah, in the mystery-solving itself.”

“Then let’s go!”

“But it’s the same day, right? Reservations might be closed already.”

“It’s fine, it’s fine.”

Yamamoto-san scanned the QR code on her phone and opened the reservation page. She was smiling and seemed excited, always so positive. I felt like I could enjoy any event with Yamamoto-san by my side.

“Hmm, all the reservation slots are full.”

“Too bad. I really wanted to go with you, Yamamoto-san.”

“If you feel that way, I’ll try a bit harder.”

Yamamoto-san called the number listed on the flyer. Apparently, there are sometimes last-minute cancellations that haven’t been updated online. Sure enough, her efforts paid off.

“Yes, yes. I understand. Thank you.”

After hanging up, Yamamoto-san gave me a peace sign.

“They said there’s one spot available for a pair, so we can join. It’s in two hours, just in time for lunch.”

“Impressive. Thanks, Yamamoto-san. I should be the one doing this kind of stuff.”

“As long as Sotomichi-kun is happy, that’s all that matters.”

This might be my first time at an event like this. I’ve attended otaku events with Suzuhara, but those felt more like live concerts. Participating in an event with everyone involved, aside from school activities, is new to me.

I guess couples include these kinds of events in their date plans. Karaoke or bowling can be fun, but they lack a romantic feel and can get boring if repeated. Even events like Christmas or Valentine’s Day, which feel like taunts to us non-popular folks, probably serve as appreciated themes for couples to spend time together.

After finishing our steaks and hamburgers at the Western restaurant—and marveling at Yamamoto-san’s appetite—we headed to the venue for the real-life mystery-solving game.

We traveled four stations, exited the station, and walked toward the residential area. The venue was down a narrow alley I’d hesitate to enter alone. At the entrance, marked by event flags, was the reception desk. Feeling a mix of anxiety and excitement, I took the lead—but then, a certain possibility crossed my mind, and I hesitated to join the line.

Perhaps my ears had picked it up unconsciously. Given the event’s proximity to the school’s nearest station, it was a distinct possibility.

“Oh! Isn’t that Yamamoto-san?”

“Seriously!? It is! She’s so cute even in casual clothes… Wait, who’s that guy next to her? Her boyfriend?”

A group of four male students, presumably in the same grade as us, were walking behind us. Yamamoto-san’s fame is such that there’s no one in school who doesn’t know her, and even outside of school, many students are familiar with her name. It wouldn’t be surprising if one of them were attending the same event.

I don’t mind being the subject of rumors. The real issue is Yamamoto-san’s reputation. Just as people are already speculating whether I’m her boyfriend, being seen on a date with her would only complicate matters further. Yamamoto-san needs to maintain her image as a pure and innocent character at school.

“Sotomichi-kun, let’s go in.”

Yamamoto-san pulled my hand, leading me into the venue. She must have known people were talking about her. Given her keen hearing, she might have noticed even earlier. Yet, she didn’t avoid the situation and joined the line, suggesting she was prepared to face acquaintances from the start.

If Yamamoto-san is okay with it, so am I. I’m not the same person I used to be. Thanks to Miyu, my appearance has improved, and physically, I have the stamina to reassure any girl. Now is the time for me to stand tall as a man.

“You must be Yamamoto-san, who called earlier. Please take a seat at table number three and wait for the pre-event briefing.”

We were given numbered tags and envelopes, then guided to our seats. The room was dimly lit, with circular tables arranged in front of a stage, each marked with a corresponding number. We took our seats, and the classmates who entered after us sat at a nearby table. One kept glancing at Yamamoto-san, two were whispering, and the last was on their phone, likely spreading rumors on SNS.

“Um, you’re Yamamoto-san, right? Didn’t expect to see you here. Are you out with someone?”

“As you can see. Nice to meet you, I think?”

“Yeah! I have a friend at Higashikō…!”

Yamamoto-san smiled and answered even the most obvious questions. This is probably a daily occurrence for her, regardless of whether I’m around.

I could confront them directly, but that would only worsen Yamamoto-san’s situation. If I act like a quiet, unassuming otaku, it’ll make it harder for Yamamoto-san to explain the situation. I think the determination I’ve built up from firmly standing my ground against my sister is what’s pushing me forward now.

“You don’t know him?”

“Nope, not at all.”

“I see. Must be tough for Yamamoto-san.”

“I’m used to it. Hehe, thanks.”

When I intervened, the guy who was talking to Yamamoto-san looked annoyed. Given that we’re on a date, him approaching her so boldly must mean he’s underestimating me.

“Wait, is that guy your boyfriend!? I heard you’ve never dated anyone before!”

“I don’t know about those rumors, but he’s not my boyfriend.”

“Oh? Then, after this, let’s all hang out! I’ll call some girls too!”

The guy was desperate to connect with Yamamoto-san. His friends behind him were making lewd comments while staring at her. They didn’t realize how their words were only hurting their chances.

“We have plans until evening, so we’ll pass.”

“Huh… really? You mean, like, that kind of thing?”

In the general male community, Yamamoto-san is seen as a virgin, so they don’t assume she’d engage in nighttime activities. Many probably think that with them, she might… But the common belief is, “Yamamoto-san, so pure and innocent, wouldn’t have sex with anyone, including me,” and they can’t accept the idea of such a man existing.

“Whether that happens is entirely up to him.”

Yamamoto-san pinched my T-shirt and leaned closer. Hey, everyone’s going to be jealous.

“Don’t worry, it’s not happening.”

“There you go.”

“Not happening!? What, are you… in the industry or something?”

“Not at all. Looks like the explanation’s starting.”

I forcibly ended the conversation. For now, I’m treating Yamamoto-san as someone unrelated to intimacy. We agreed not to do anything today, so it’s not a lie.

When Yamamoto-san jokingly asked, “Really not doing it?” I brushed it off. Her attitude seemed arrogant to them, and I think I played my role well as someone who’s not her boyfriend today. Yamamoto-san’s teasing skills are famous, after all.

As the lights dimmed, a man with a microphone appeared on stage to explain the mystery-solving rules. The concept was that we were intelligence agents abducted by a mysterious organization, poisoned to die in three days. We had to decipher the secrets left by our predecessor to find the antidote and escape. The eerie decorations added to the horror atmosphere.

We were led to partitioned rooms, where the real mystery-solving began. There were alternating 15-minute “days” and 5-minute “nights.” During the night, exploration outside the room was restricted. Daytime was for free exploration, and nighttime was for security checks. If caught by guards, we’d be sent back to the room, unable to do anything until the next day.

On the table were crossword puzzles, a locked treasure chest, a pen, and the explanatory pamphlet we received earlier. The goal was to unlock hidden mechanisms in both the small and large rooms to find new clues.

“Definitely a real-world mystery game. Let’s start with what seems solvable…”

“Yeah yeah. Do your best, Sotomichi-kun.”

Yamamoto-san just watched from behind, arms crossed. I hope she’s not planning to leave everything to me. The clearance rate for this event is less than 10%, making it quite challenging.

“Half of the crossword can be solved directly. The rest requires reinterpretation. Yamamoto-san, any ideas?”

“Is it okay if I help?”

“Of course! Let’s do it together. The missing words here should match the keywords posted around the venue. Yamamoto-san, do you remember them?”

“Ufufu, they’re all in my head. Should I just answer?”

“Please. I’ll struggle if we don’t have extra time.”

When it comes to finding hidden hints, my experience with games has given me a decent ability to pinpoint them. However, my problem-solving skills beyond that are practically nonexistent. If possible, I’d like to clear this smoothly and feel good about it. There’s no better option than to borrow the brain of the genius beauty standing next to me.

“Here, we match the keywords to the days of the week… and use the ruler we found earlier as a reference for these letters.”

“I see. The oddly prominent dots on the pamphlet are markers. Aligning this with the wall…”

With Yamamoto-san’s intellect added to the mix, the puzzles were solved at an incredible pace. At first, Yamamoto-san was hesitant, but as our tasks became clearer, she grew more enthusiastic. She seemed to feel a bit self-conscious about how quickly she could find the answers, but for me—who used to dominate offline games with online cheat strategies—this overwhelming advantage felt exhilarating.

“Can we reach the final answer at this point?”

“No way. We’re missing too many hints. I think the real challenge starts with using the key from the treasure chest.”

“But there’s no keyhole anywhere. We have to find that too.”

Despite the complexity, brainstorming possibilities was enjoyable. The treasure box’s lock required a code obtained from a diagram that also served as a map, leading us to a location where we needed to use a key. Engaging in this hands-on puzzle-solving and exploration was thrilling. When we opened the large box we found, it contained a school uniform—so, it seemed the goal was to have her cosplay in it.

Though it was a simple ensemble of just a hat and jacket, Yamamoto-san, disguised as a security guard, exuded a dominantly erotic aura reminiscent of a sadistic instructor. The penlight tucked into her breast pocket seemed uncomfortably confined.

“Keep fantasizing about getting it on with your little sister, and I’ll have to arrest you.”

“If you take away even that freedom, my balls’ll burst and I’ll die, so please, just spare me.”

The true purpose of this uniform was to facilitate nighttime exploration. By saluting any security guards we encountered, we could avoid scrutiny. Beyond a door accessible only at night lay the crucial item needed for the antidote—without it, escape would be impossible.

“So, if we stick on this detox seal, we’ll clear the game by day four, huh?”

“That’s right.”

“As long as we solve the puzzles, it’s surprisingly straightforward, huh?”

With such carefree thoughts, I ended the second night, complacent because Yamamoto-san had helped me. But as the final night approached, a sudden unease crept into my mind—an instinct honed from years of anime and games, a so-called “death flag.”

“Yamamoto-san, that entrance over there—it’s not locked at night, right?”

“Since I’m out and about, it’s never been used before.”

What we truly needed to do wasn’t cure the poison—it was to escape. Even if our bodies recovered, if we couldn’t get out, it’d be game over.

“Remember that first announcement? Something about security thinning out after three days. What if we get locked in then? Can we use this mysterious metal piece to make it look locked?”

“Sotomichi-kun, that’s a great idea.”

After manipulating the padlock and completing the antidote, we finished the third night. As the broadcast played, security guards began checking the locks, and groups that hadn’t tampered with theirs were immediately game over.

We, however, successfully escaped. Returning to the reception after the game, we were told we were the only ones to escape in this session. We received a commemorative clearance certificate and headed outside, where the same group of guys approached Yamamoto-san again.

But as I walked ahead, almost commanding her to follow, they seemed to lose their words upon seeing her happily comply. Realizing that even the kind Yamamoto-san chooses her close companions, and that they weren’t among them, they quietly backed off.

Yamamoto-san is quite the actress. I never knew it could be so hard to reject someone without hurting their feelings. If I ever fall in love in the future, I’ll have to be careful not to inconvenience any girl.

“Feels like ages since I’ve been outside. The game flew by when we were focused.”

“I had fun too, for the first time in a while. Glad it was with you, Sotomichi-kun.”

Yamamoto-san, oblivious to the summer heat, beamed and clung to me. This was getting past the point of mere misunderstanding. Her straightforwardness made me flush, raising my temperature further.

Sensing my thoughts—I didn’t do anything special—Yamamoto-san shot me a gentle look, as if to say, That’s not true.

“I usually solve these events too fast, so I’m bad at pacing with others.”

“Then why today?”

“I figured it’d be okay with you. Just a feeling.”

Yamamoto-san switched from a peace sign to scissors, chopping the air: “And that feeling was spot-on,” her gratitude clear. What set me apart from other guys, I wondered, but if she was happy, I didn’t need to know.

“I just didn’t want you to look bad. By the way, did you notice the final lock trick?”

“Nope. Totally missed that one.”

Yamamoto-san’s smile was unmistakably genuine. Even she had blind spots, perfect yet flawed.

“Hey, Sotomichi-kun, wanna hit up an internet café?”

“Sure. Got a manga you wanna read?”

An internet café with Yamamoto-san? This was heading into risque territory.

“I need to blow off some steam.”

Yamamoto-san placed her finger on her lips, giving me a longing look. Ah, so that was it. She didn’t notice the last puzzle not because she missed it, but because her mind was entirely on something else—something lewd. The stress must have been overwhelming, despite her calm demeanor. Even someone like her finds being approached by such guys exhausting.

I had planned not to have sex today to save my energy for the real deal with Yamamoto-san. But with her directly asking for it, I have no reason to refuse.

However, choosing a net cafe instead of a love hotel might indicate she’s not ready for the real thing yet. Though, I’m not sure if students like us can even enter a love hotel.

“Got a place in mind?”

“Yep. Let’s head back to the station.”

We boarded a train in the opposite direction, returning home while it was still light. Yamamoto-san, sensing no acquaintances nearby, held my hand as we walked to a café near the station.

“Let’s do it here.”

Her choice of words left no room for misunderstanding. Unlike when I came with Sachiko, this net cafe had completely private rooms instead of partitioned spaces. Here, we could openly engage in intimate acts without fear of being reprimanded. Of course, the rules prohibit acts against public order and morals. But we’re going to do it anyway. Maybe Yamamoto-san chose this place precisely because it’s somewhere we’re not supposed to—adding to the thrill.

We checked in, settled into the couple’s booth, and the moment we put down our bags, Yamamoto-san closed the distance, unable to wait any longer.

“Mind if I have Sotomichi-kun strip?”

Seated on the black vinyl floor, Yamamoto-san clapped her hands, grinning. The sweat on her forehead hadn’t even dried yet.

“What about you? Aren’t you stripping?”

“If you really want me to, I will. But right now, I just want to pleasure you and make you cum—all me, nothing from you.”

The speed of her escalation spoke volumes about her pent-up stress. Her words were unfiltered, raw—not just from built-up desire, but years of frustration. Men always climaxed too quickly, denying her the slow, pleasure-driven domination she craved. Her eyes sparkled with hearts.

“Then… at least let me undress you.”

“Yes, I’d love for you to serve me that way.”

Yamamoto-san peeled off my T-shirt, then lunged forward, latching onto my nipple. The sudden pleasure was overwhelming; I instantly soaked my pants with pre-cum.

“Ah… Yamamoto-san, too eager…!”

“Mmm… slurp… can’t help it… suck…”

After ravishing my chest, her mouth trailed up my neck, her tongue ravaging my skin. Her right hand slipped into my pants, stroking my hardened length from tip to base.

“Y-Yamamoto-san… nnh… ahh… t-that’s…!”

Anyone else would’ve already climaxed. Her past partners never lasted this long, and now, with me, she showed no mercy—years of unfulfilled desire fueling her intensity.

“You’re so hard… love it… munch… Sotomichi-kun, I really love doing this… slurp, suck… ahh… mmph…”

Her voice, aching with longing, heightened my sensitivity. She flicked her tongue at my nipple, eyes locked on mine, face flushed with arousal. Her hands traced every inch of my upper body, each touch turning skin into erogenous zones, forcing moans from my lips.

Confirming my pre-cum-coated length, she stripped me fully, pinning me down. Her mouth returned to my neck, her hand stroking me while her free hand caressed my inner thighs. She grazed my sac, fingers trailing my skin—relentless, teasing, building my arousal.

In a frenzy of pleasure, she devoured me with deep kisses, her tongue worshipping my body. Focusing on my nipples, she used her feet to maintain stimulation, her thighs stroking me rhythmically.

With deliberate sounds—slurp, squish—she sucked my nipples, her toes deftly milking me. The dual assault was overwhelming; my cock spewed copious pre-cum.

“Uhh… gnn… ahh…!! Aah… no… can’t… haa… ahh…!!”

Her toes squeezed and twisted, sometimes grinding, sometimes gentle—until memories of Miyu in the bath surfaced.

“Ah… c-cumming… ahh… ahh…!!”

Splurt… splurt… my semen coated my abdomen, dripping onto Yamamoto-san’s feet. I’d climaxed without permission, in under fifteen minutes.

“Huh? You… came? That good?”

“It was… unlike anything before…”

“Thinking of Miyu again?”

I nodded. Since I’d climaxed, it meant this scenario was in my fantasies about her.

“What do you imagine Miyu doing to you?”

“Please… don’t make me say it… I feel terrible enough…”

Miyu would never do something so lewd. Yamamoto-san knew it, but she didn’t press—aware my arousal tied to Miyu must stay hidden.

“Sorry for cumming without permission.”

“Hehe. I didn’t say you couldn’t. Let me clean you up.”

She licked her feet clean, then my abdomen, her long tongue mirroring what Miyu had done that morning. My spent cock twitched, hardening again as she worshipped my body.

“You’re so horny. How many times do you jerk off daily?”

“I-I don’t… when I’m alone, I can’t stay hard…!”

“When you’re alone?”

My tone slipped. She caught the nuance—realizing I hadn’t fantasized about her during solo sessions.

“Uh… I had a girlfriend once… never told her about using Miyu… but…”

“I see.”

She let it go, choosing not to dig deeper. My insatiability, tied to Miyu, must remain her secret.

“For now, I’ll pleasure you with my mouth… slurp, suck…”

Centering on oral, she denied me release, lavishing attention from ears to toes. Her smirk hinted she knew what I was hiding.

“Gulp… slurp… no cumming till later. Save it for the bed.”

For over an hour, her relentless mouthplay left me hoarse, bound to cum tomorrow—if she ever let me.