Prologue

I, Touma Itohara, have a sister who is one year younger than me. Her name is Saki Itohara.

In other words, I’m the oldest child.

Because we are so close in age, we often argue with each other, but since my parents are busy with work, I have been living with my sister.

If you look at it from a normal point of view, I think we have a pretty good relationship.

“Nii-san, I’d like to invite my friends over tomorrow.”

One day, while we were both in middle school, my younger sister asked me such a thing.

“…What’s the point of telling me…? You should tell mom or dad instead.”

“I did tell them, but they said I could do whatever I wanted as long as I kept my room clean and didn’t do anything weird.”

“Well, I don’t have a job. Besides, I don’t mind. You can call me if you want.”

“Yeah, thanks.”

I had no reason to refuse, so I agreed.

Without knowing that this choice would have a big influence on me in the distant future─.

“Hello. I’m sorry to bother you.”

“…O-Ohh. Welcome. Please take your… time.”

My sister brought in a beautiful girl that made me think she was some kind of celebrity.

In addition to her beautiful appearance, she also bowed politely to me and greeted me, and I was taken aback.

“Okay then, Rin-chan, this room over here! Nii-san, can you bring us some juice and snacks?”

“Aight.”

“N-No, you don’t have to do that… Don’t mind me.”

“Don’t worry about it.”

Considering that the other person was younger than me, I had no intention of speaking to her in honorific terms from the start, but somehow the atmosphere naturally made me speak in honorific terms.

Perhaps I had been taken in by her atmosphere from that moment on.

“Here. Sweets and tea.”

“Thank you very much!”

“Huh, there’s no juice?”

“The only decent thing I could find was chocolate. Chocolate with tea is better, right?”

“Well, that’s true. Nice choice.”

“I’ll go back now, and you two can enjoy yourselves.”

That was all I said at first.

She and I only greeted each other and didn’t even have a proper conversation.

That was the norm.

In the first place, it is not unusual for the friends of a friend to be strangers.

It’s not every day that a friend of a friend is a stranger, much less a friend of a family member who is close in age to my sister of the opposite sex.

Although I was overwhelmed at first, I didn’t think anything of it after that.

However, my sister and her seemed to get along very well, and she began to visit my house regularly.

In addition to that, my sister’s personality often made it difficult for her to come home for errands even though she had promised to.

“I’m sorry for this, okay? She never forgets her promises, so I guess she’s running late for something. She’ll be home soon.”

“No, no, don’t worry about it.”

She smiles at all times.

It was impossible not to be charmed by the smile of an overly well-groomed and pretty face.

If we ever make eye contact, we both get flustered and behave strangely.

“……”

“……”

It was a time when the two of us had to be in such an awkward atmosphere.

From that time on, my girlfriend, Rin Mamiya, and I began to have a strange and distant relationship.

“Ah, that reminds me. Rin, she’s going to enter the same high school as Nii-san.”

“…Oh, really?”

It was the end of spring break and the start of a new school year tomorrow when my sister suddenly brought up the subject.

I know the person whose name came out of my sister’s mouth very well myself.

She stopped coming to our house after the exam season started, but she used to come to our house often until just a few months ago.

By the way, my sister went to a school for a major in music, so she didn’t go to the same high school as me.

“But I don’t really have anything to do with her, do I? You brought her here in the first place, so what’s the point of meeting her?”

“Well, that may be true. But if something happens…”

She is very close to her and cares about her a lot.

It’s a good friendship, but I don’t want to go out of my way to get involved, no matter how much my sister asked me to.

But I know her well enough to know that she is a good girl.

So, if she is in trouble, it would be better if I could support her in some way.

However, I feel that this is not the kind of supportive relationship that my sister has in mind.

I was hoping that we could just support each other as senpai and kouhai in the same high school.

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Translator’s Afterword: This series has 34 chapters including prologue and epilogue for the first volume.