My Little Sister Is the Best F*p Material

Volume 5 Chapter 10: A Serious Romance with Yamamoto-san

As I walked between the station and the bus stop, I thought I heard a familiar voice. I looked around and immediately spotted the source—Yamamoto-san and Kawafuji. Despite the bustling crowd and chatter, the human ear seems to pick out specific sounds. They noticed me too, leading to an awkward reunion.

Before Kawafuji dragged me into the department store, Haruka whispered, “Is that Yamamoto-san?” I nodded, and her eyes lit up, even though she’s supposed to be into lolita fashion. Given that Yamamoto-san resembles Miyu in appearance, except for her height and expression, maybe Haruka has a type for elegant, busty women. I was already dreading the complications ahead, so my mind wandered.

“Wait, why is Nanako talking to Sotomichi-kun?”

“Because I have something to discuss with him. You should just catch your train.”

Kawafuji seemed eager to send Yamamoto-san off somewhere, but Yamamoto-san was resisting.

Yamamoto-san wore shorts and a mini shirt, an outfit that was already too stimulating. She had one side of her hair braided, with a teardrop-shaped blue earring glinting near her ear—an unusually dressed-up look for a casual visit to the department store near the station. Kawafuji, with her sleek shoulder-length hair, wore a cool, mature outfit centered around a long skirt. Together, they were a stunning pair, almost like sisters.

Whether out of curiosity or intuition, Haruka, who had been quietly standing beside me, spoke up.

“Is Yamamoto-san your classmate, Onii-san?”

“Huh? Ah, yeah. I am… And who’s that unbelievably beautiful woman over there? Your second sister?”

As if.

“I’m Haruka, Miyu’s friend. If you don’t mind, would you like to walk around the department store with me while Onii-san and Kawafuji talk?”

Kawafuji, who had been trying to send Yamamoto-san to the station, glared at her. But Yamamoto-san, who seemed reluctant to leave, eagerly agreed to Haruka’s proposal. Kawafuji reluctantly decided to prioritize her conversation with me.

“──What do you want to talk about?”

Kawafuji and I stood side by side near a travel agency’s pamphlet display.

“What’s with Kanade’s attitude?”

Her sharp gaze pierced me as she asked, cutting straight to the point without needing details.

“If you skip to the end like that, I have no idea what you’re talking about. What’s wrong with Yamamoto-san?”

From my perspective, aside from the awkwardness when we met, things seemed no different from how they were in class.

“Are you serious? Before summer break, there were even rumors about you being Kanade’s boyfriend. You haven’t noticed her decline?”

“Ah… there were some misunderstandings about that. We haven’t met since summer break started, so I’m not sure what’s going on.”

If Yamamoto-san’s attitude has changed recently, it’s probably because I rejected her. But since Yamamoto-san hasn’t told Kawafuji yet, all I can offer is a harmless lie. I didn’t think Yamamoto-san’s behavior was any different from how she is at school; if anything, she seemed like a different person when we were alone compared to her usual elegant self.

I thought that if I insisted I didn’t know, Kawafuji would conclude I was uninvolved. But it seems Yamamoto-san had shared more information than I realized.

“So something did happen. I know you’ve been meeting her even after summer break started.”

My lie was immediately exposed. Since I’d tried to defend Yamamoto-san, I was seen as an accomplice.

“Ugh. I had such high hopes this time. I guess I was foolish to trust and leave it all to you.”

Kawafuji sighed heavily, her gaze blankly falling on a travel magazine for nearby areas. It was the height of summer vacation, yet she seemed to be looking for a consolation trip.

“Are you talking about getting Yamamoto-san a boyfriend?”

When I was thinking about a gift for Miyu, Kawafuji had told Yamamoto-san to get a boyfriend quickly, saying she’d introduce someone. Back then, I was dismissed as insignificant, but if anyone would do, I—rumored to be Yamamoto-san’s boyfriend—might have been the first choice.

“Not necessarily a boyfriend, but someone to support Kanade.”

“Support Yamamoto-san…? With what? Can’t Kawafuji do it?”

I never thought Yamamoto-san, who can handle anything on her own, needed support. Knowing her troubles, I figured she just needed a sex partner, but why would Kawafuji need to take responsibility for that?

Before summer break, Kawafuji had been introducing men to Yamamoto-san, who was tired of confessions, and Kawafuji, who was asked to introduce Yamamoto-san, needed a boyfriend as a deterrent. But why has this escalated to needing someone to support Yamamoto-san?

“Kanade’s inability to enjoy life is partly because of a man. If we’re going to fix it, it has to be with a man. You’ve heard the story, right?”

“I’ve heard bits and pieces, but not that it’s stopped her from enjoying life. I thought Yamamoto-san was one of the most joyful people I knew.”

Born with exceptional abilities, a bright personality, and many friends, she seemed to enjoy life without any troubles aside from sex. She even said she didn’t want sex.

Yamamoto-san always seems to enjoy everything. When I told her about the offline meetup plans, she encouraged me because she’s that kind of person.

“Has Kanade mentioned her part-time job?”

“She’s working at an izakaya for 820 yen an hour. She could earn more as a model, so it seems like a waste in that sense.”

“That’s it. She could aim higher if she wanted, but she’s settling for less and wasting her life… It’s frustrating to watch.”

When Kawafuji said this, her tone was so sharp it was hard to believe she was talking about a friend.

“Do you actually dislike Yamamoto-san?”

“Of course not. I adore her. To the point of obsession.”

Kawafuji closed her eyes and traced the same piercing in her ear as Yamamoto’s with her finger as she spoke. It was an unexpected statement, but knowing Haruka, I could tell there was no sexual nuance in her words, unlike with Haruka.

However, Kawafuji seemed to realize her slip, glanced at me, and then checked to make sure Yamamoto wasn’t around. She pointed to a nearby bench, indicating we should sit for a longer conversation.

“I’ve known Kanade since middle school. We met when she joined the basketball team. I’ll never forget how she looked back then. She was phenomenal.”

Kawafuji spoke calmly, but with a rare, almost nostalgic smile.

Yamamoto’s presence alone was enough to guarantee victory in a team sport. There are occasional prodigies in professional sports who force rule changes, but just how extraordinary was she?

“She was an ace in every sport, always at the top in national mock exams, and with her looks, she was practically invincible.”

“She was that amazing? No wonder you’d say she’s fallen compared to now.”

Even now, she’s at the top of her class in tests and dominates in gym class. Combined with her appearance, I thought she was already perfect. But Yamamoto’s talent seems to surpass even the best in the school.

“Still, it’s up to Yamamoto how much she strives, right?”

“True. If Kanade were that kind of person, I wouldn’t have complained.”

Kawafuji’s words were cryptic. Maybe this is what Yamamoto meant when she said, “You only know the current me,” during our time at the apartment.

During a pause in the conversation, Kawafuji took out her phone and typed a message, likely responding to Yamamoto. She quickly put her phone away and continued.

“And if her attitude this summer had been the same as before, I would’ve left her alone. But…”

Kawafuji looked straight into my eyes.

“I can’t put it into words, but when she talked about you, she was different. Even if something happened, I don’t think she’s given up completely. As long as she feels that way, I want to help, even if it’s unnecessary.”

I don’t know Yamamoto’s past, so I can’t understand Kawafuji’s feelings. But if Yamamoto hasn’t given up, then the reconciliation Miyu and I are planning might not be in vain.

It seems Yamamoto cares about me more than I thought. If that’s the case, I can’t run away without resolving things. If Miyu knows the right way to face Yamamoto, I should follow her lead, even if it means setting aside pride and reputation.

I can’t predict how Kawafuji will react, but if it helps Yamamoto find closure, it’s worth it for all of us. Even if it means Miyu and I have to abandon our ethical standards as a couple, I now believe it’s something only Miyu and I can do.

“Kanade’s getting curious about us, so we should go. Sorry I couldn’t give you more details, even though I took up your time.”

“No, it’s fine. I’m glad we talked. If possible, I’d like to stay friends in the second semester too.”

“Can’t promise that. Maybe if you become Kanade’s boyfriend.”

She ended as coldly as ever.

“Sotomichi-kun! So it’s my turn next, right?”

“What are you talking about?”

Yamamoto rejoined us with unusually high energy. Even the silent Haruka seemed satisfied. Perhaps she’s good with younger people, like with her younger brothers.

“Weren’t you supposed to go somewhere, Yamamoto-san?”

“Don’t worry about it. It’s nothing important.”

Yamamoto smiled brightly at me but signaled to Kawafuji with her eyes. It seemed she was insisting on having her way this time. Kawafuji finally gave in, saying, “Do as you please,” and left.

“Haruka-chan, is it okay with you?”

Yamamoto-san lowered her gaze and asked Haruka beside her.

“Alright. I’ll talk to Onii-san for a bit and then head home.”

Haruka approached me from Yamamoto-san’s side and whispered this.

“I heard the situation from Miyu and fed her some truths and lies.”

What an unnecessary thing to do.

“I’ve also informed Miyu about our situation, so you’ll likely receive instructions from her soon. Yamamoto-san seems quite affected by you, so please be gentle with her.”

Haruka deliberately emphasized “because of you” and then bowed slightly to Yamamoto-san before leaving. Yamamoto-san waved cheerfully at Haruka, who seemed to have become friendly with her, but as soon as Haruka was out of sight, she turned to me with a slightly pouty expression.

“Why do you always attract such cute girls, Sotomichi-kun?”

Clearly displeased, Yamamoto-san complained but still snuggled close enough for our arms to touch. Even though I chose Miyu, seeing me get along with other girls who are just as attractive, if not more so, must bother her.

“It’s less about being liked and more about being dragged into things…”

Both Miyu and Yamamoto-san have their own troubles, and I was chosen to help resolve them. I’ve put in effort, but ultimately, it’s just good compatibility.

In Miyu’s class, the girls have loose morals, and my status as Miyu’s brother makes their advances toward me intense. There’s so much inappropriate content that I can’t explain it well. And Halmaki’s personality didn’t help either.

“Maybe you emit some kind of pheromone that attracts women.”

As a sign of her displeasure, Yamamoto-san linked arms with me.

“Everyone seems to do it… is it okay? Haruka-chan and that Yuka-chan said they went on dates and got cozy with you. Even Nanako wants to be alone with you.”

So, Haruka did feed her some truths and lies. At first, Yamamoto-san seemed confident, pressing her chest against me, but her tone weakened, and she stopped clinging to me. She alternated between sticking close and pulling away, fighting an invisible battle.

“This much is just a greeting… yes, so, pressing my chest like this… in Western countries… it’s quite common…”

Watching her adorable struggle, even as Western countries suffered from serious reputation damage, I observed for a while. Unfortunately, the invisible force proved too strong for her. In the end, she stiffened her arm, distanced herself from me, and began to apologize with faint tears of frustration.

“Uuu… I can’t do it…! I said I wouldn’t be greedy anymore… sorry, Miyu-chan, Sotomichi-kun…!”

“I-It’s fine. Neither Miyu nor I would get mad over this.”

It seems Haruka’s misinformation led her to attempt something improper, but she gave up at the arm-linking stage. If only Yuka had this much restraint.

“Sigh… I didn’t realize I was such a terrible person…”

Yamamoto-san sighed heavily and played with the end of her braided hair. Usually, the ends are near her chest, but now they’re up by her shoulders, giving her a fresh, summery look with her collarbone exposed.

“Don’t say that. You helped me gain confidence, and your consideration for others is one of your strengths.”

“But when I saw you and Haruka together, I felt so uneasy… even though I tried to accept it, I haven’t forgotten anything, and I don’t know what to do.”

Yamamoto-san tightly pressed her lips together and gently traced the earring exposed by her braided hair. Despite deciding to distance herself after being rejected, seeing others get along with the person she cares about has left her with unfamiliar emotions.

She’s been rejected many times before, but being turned down before even dating is a first. Her feelings are at their peak, and being forbidden to pursue them is unbearable. But I don’t know why she’s so attached. It feels different from just wanting a boyfriend for sex.

Following Miyu’s instructions might reveal the reason. I shouldn’t ignore the cryptic message she sent me.

I’m not just being led around. I’m right in the middle of this, so I should take action and responsibility. After hearing Miyu’s, Kawafuji’s, and the other girls’ words, I made up my mind.

“Since we’re here, let’s take a walk.”

Yamamoto-san, who had been dejected beside me, widened her eyes and lit up at my words.

“Yes!”

With Yamamoto-san lightly approaching me, we headed to the department store’s shopping floor. This is the first step in reconciling with Yamamoto-san. I’ve taken it.