For Some Reason, My Little Sister’s Friend, Who Is Totally Devoted To Me

“Nishiyama-san.”

“Aoi is fine.”

“Okay. Aoi-san.”

“What?”

　After a brief silence following Nishiyama’s revelation of my love of big breasts, Shiori-chan spoke up.

“Onii-san, did you say anything else besides that you like big breasts?”

“…Wah!? *Cough, cough, cough*! No, don’t bother digging into that.”

“That’s no good. This is my chance to ask my boyfriend about his sexual habits. I can’t let this opportunity slip away.”

“C-Can we just stop about this? I don’t think anyone will benefit from this… Nishiyama, don’t say anything unnecessary anymore, okay?”

　I coughed profusely and began to persuade Shiori-chan.

　I glanced at Nishiyama and gave her a nudge.

　But Nishiyama raises the corner of her mouth mischievously and puts her index finger on her mouth.

“Don’t tell Junpei-senpai, okay?”

“Okay~. Let’s keep it a secret between us.”

“Erm, I don’t think that’s a conversation you should be having in front of me, is it?”

　I smiled bitterly and cautioned them against talking about something that would affect my privacy. I’m not sure if it’s a convenient feature that prevents my voice from reaching them, but Nishiyama said with an indifferent face.

“He said that having big breasts and being older are absolute requirements. He also said that he would prefer a woman who was quiet, neat, and had good black hair. Oh yeah, he also said that he’d rather be pursued than chased, and that he doesn’t like to be pestered.”

“I’m totally out of the loop…”

　Nishiyama began to talk about my preferences in women in an eloquent manner.

　When Shiori-chan heard this, she had a pale face and was in a state of mindlessness.

　Damn, when Nishiyama was asked about my preference for the opposite sex, she answered honestly without even thinking twice.

　I had completely forgotten about Nishiyama’s lack of reservation in speaking.

“But Shiori-chan, you’re dating Junpei-senpai, aren’t you? How did you get him? I don’t know how you managed it.”

“I just told him how I felt about him, that’s all. Well, we’re dating, but it’s like a trial period.”

“Trial period? …So it’s more like friends but less than lovers?”

“No, we are definitely lovers. But I’m not sure if it’s official yet.”

“I don’t understand it fully, but it’s not exactly like a formal relationship, is it?”

“That’s right, but… what about it?”

　Nishiyama put her hand on her chin and pondered in silence for a few seconds.

　She then looked up as if she had thought of something, and caught me with her brown eyes.

“Junpei-senpai, would you also like to have a trial relationship with me?”

“”Eh?””

　The voices of Shiori-chan and I overlapped.

　When I responded to the unexpected suggestion with my eyes wide open, both Shiori-chan and I went rigid on the spot for a while.

　While I was hesitating about how to react, Shiori-chan spoke up first.

“What are you saying all of a sudden!? Are you trying to steal my Onii-san in front of his girlfriend?”

“Eh, it’s just a trial, isn’t it? Then why not?”

“That’s not good! I’m not giving you Onii-san!”

“You say that, but what about Junpei-senpai? Can’t you go out with me on a trial basis?”

　She stared straight into my eyes as if looking into the depths of my eyes. I didn’t need to think about the fact that this wasn’t some kind of joke.

　My heart beats faster and faster. I swallowed the spit in my mouth with a gulp, took a breath, and looked back into Nishiyama’s eyes. I bowed my head, as sincerely as I could show.

“…Sorry. I can’t do that.”

“…Is, that so? Well, it’s true that Junpei-senpai doesn’t have the fortitude to do two-timing. I knew that. So please, don’t bow your head to me like that, after all, I was the one who suggested it. Well, I did have a little bit of expectations but… I’m going to make this clear, I’m rather serious about liking Junpei-senpai, you know?”

“…Un. T-Thank you for that… And I’m sorry for not noticing.”

“It’s okay, don’t worry about it. And I’m not going to give up either.”

“Eh?”

　Removing her gaze from the stunned me, Nishiyama declares war on Shiori-chan.

“Shiori-chan, don’t think you’ve won this one, okay? I’ll definitely make Junpei-senpai’s feelings turn to me… Well, I have bigger breasts than you. It’s just a matter of time.”

“Nha!? I-I’m still developing. By the time I’m in high school, I’ll have larger…!”

“Yes, yes. I hope that happens. Well, I’d better get back to work.”

“I-It’ll definitely get bigger…”

　Nishiyama left her seat and walked back to the kitchen, as if she was nursing a baby. Shiori-chan bites her nails and watches her back with a grudge.

　With Nishiyama out of sight and no customers around, only the soothing low-tempo background music fills my ears.

　I can still feel the lingering effects of Nishiyama’s direct expression of affection towards me. As I’m struggling to figure out what to say, Shiori-chan interrupts my thoughts and wraps her arms around me.

“I was so careless. Onii-san, you’re not going to do two-timing behind my back, are you?”

　She looks up at me and asks with concern.

“I won’t. Like Nishiyama said, I don’t have the guts to do it.”

“But there is a possibility that you will switch from me to Aoi-san, right?”

“T-That’s…”

　I couldn’t deny it right away.

　I had only just started dating Shiori-chan. I’m still in the process of reevaluating Shiori-chan as the opposite sex. Therefore, I didn’t have enough evidence to make a firm statement.

“I don’t have that kind of big breasts…”

　Shiori-chan lowered her gaze and muttered to herself.

　The air of unpleasantness prevailed throughout the room.

“It’s not like I like big breasts that much, you know?”

“Really?”

“Ah…Well, yeah.”

“Onii-san is a terrible liar, isn’t he?”

“Ugh, no, I don’t think so.”

“Oh, yeah. Rub my breasts for me, Onii-san.”

“…Ha? What are you saying suddenly!?”

“I’ve heard that if you rub your breasts, they get bigger. Kinda like breastfeeding I suppose, yes breastfeeding.”

　Shiori-chan smiles softly and holds out her body for me to squeeze her breasts.

　Her unabashed energy was now at a level worthy of respect. No, this is not the time to be impressed.

　My embarrassment showed in my cheeks as I shook my head.

“You shouldn’t believe that kind of information…”

“Onii-san, you’re a science major, right? Let’s do some experiments!”

“Not all science majors like to experiment. Oh, by the way, we’re at a diner and we haven’t ordered anything yet. Can we start with the drink bar?”

“Please don’t change the subject. It’s important for the future.”

　Shiori-chan leaned forward with a slightly dissatisfied expression on her face.

　I blushed and pressed the call button to avoid Shiori-chan’s onslaught.

　Shiori-chan puffed out her cheeks in a mushy manner and spoke up.

“It’s not every day you get to rub a middle schooler’s breasts, you know? By the time you’re an adult, it’s already a crime.”

　Well, it’s true that the police are lenient towards minors…

　At least, in the short time we’ve been lovers, I haven’t had the guts to go that far. I’m sorry for being such a slob at this.