Mikoto-san said she wanted curry for dinner, but after thinking about it, I figured that she was still sick.

I couldn’t possibly make her eat a very spicy Indian curry, but she still wanted to eat curry rice, so I decided to make a much sweeter curry.

Mikoto-san took a bite of the curry and said.

“I still feel like I’m being treated like a child when it’s this sweet…”

“I made it because you told me to make it, even if it’s sweet. Does it not suit your taste?”

When I said this with a laugh, Mikoto-san hurriedly shook her head.

“No, it’s not that. Not at all. It’s delicious. Besides, I’m not very good with spicy food to begin with.”

“I’m glad to hear that.”

She insisted on doing the dishes, but in the end, I decided to do it myself.

Even though her fever had subsided, I shouldn’t make a sick person do something tiring.

Reluctantly, Mikoto-san listened to me and dangled her legs at the dining table.

Then, as if a sudden thought occurred to her, Mikoto-san asked me.

“Does Akihara-kun have any siblings?””

“No, I don’t. Well, Amane-nee-san is like a big sister to me.”

I answered as I washed the dishes.

I used to wash the dishes for Amane-nee-san, who also used to live in this home, but recently I have been washing only one person’s dishes for a while.

So, it is fair to say that things have returned to normal with the arrival of Mikoto-san.

“What about you, Mikoto-san, do you have any siblings…?”

I started to ask, but stopped myself in mid-sentence.

Mikoto-san didn’t seem to want to talk much about her family, and it seemed that she had been forced to leave the Tomi family mansion where she had originally lived.

I don’t know what’s going on, but I thought it would be better not to ask.

But Mikoto-san said calmly.

“There’s no need to worry about it. I have several siblings, but the one closest in age is my younger sister.”

“Heh.”

“But she’s only half my sister.”

“Only half?”

“We have the same father, but different mothers. It’s called “half-sister.”

“Ah, I see.”

So that’s how it is.

Somehow, I could guess why Mikoto-san’s last name is not “Tomi” even though she is a daughter of the Tomi family.

I am sure that Mikoto-san is using her mother’s surname as her family name, “Mikoto”.

I don’t know why, and I wasn’t going to go into it.

Mikoto-san said quietly

“Akihara-kun, you are on good terms with Amane-san, right?”

“Well, I think we got along well. I was always pushed around by Amane-nee-san, though.”

She is five years older than me, so I could not disobey her at all.

In return, I think Amane-nee-san took good care of me a lot.

When she lost her parents, I was in the fifth grade and she was in the first grade of high school.

Amane-nee-san took care of me as if she was seeking compensation for something she had lost.

Whenever she went fishing, to the library, or to the movies, she took me with her.

Now she is far away in a foreign country.

Mikoto-san said sadly.

“She’s Akihara-kun’s cousin, so that means she’s only a quarter sister. But you’re so close. I envy you.”

A quarter?

After thinking about it for a while, I understood.

If you count a normal sibling as one, then each cousin is a sibling of one parent, so that is one-half squared, which means that they are only one-quarter siblings.

“My sister is only one-half sister, and she hates me very much.”

I was still unsure whether I should go in and ask about the situation, and in the end, I didn’t ask anything.

I didn’t have the courage to do so.

I said instead.

“According to that calculation, that would mean that Mikoto-san is only one-sixteenth my sister.”

“Eh?”

“Me and Mikoto-san are cousins. Any of our grandparents are siblings, so, one sixteenth.”

“I see. That’s how it is.”

After muttering this, Mikoto-san’s cheeks puffed out in dissatisfaction.

“Why am I your sister?”

“No, it’s just something.”

“I’m only one-sixteenth of a sister.”

“When is your birthday, Mikoto-san?”

“It’s the eleventh of January.”

“Mine is the ninth of September.”

I won.

I couldn’t help but smile.

No, there’s no such thing as winning or losing.

Mikoto-san said with a shocked expression on her face.

“I’m … your sister?”

“Only one sixteenth.”

When I said this with a laugh, Mikoto-san stared at me with a frustrated look on her face, and after a while she started to chuckle.

” I see. Akihara-kun is only one sixteenth of a brother to me. Shall I call you ‘Onii-chan’?”

“That would be embarrassing, so let’s not do that.”

“Ha… Haruto Onii-chan… like this?”

Mikoto-san sounded rather embarrassed as she said that in a muffled voice.

If you’re embarrassed, you shouldn’t have done it.

I looked away and said, scratching my head.

“I guess it’s not so bad.”

“Akihara-kun, you’re embarrassed.”

“You’re the one who’s embarrassed.”

“I … always wanted to have a brother who was close to me.”

“I see.”

I thought about the meaning of Mikoto-san’s words.

Mikoto-san said that she is no longer able to stay in the mansion where she lived and that she and her sister are on bad terms.

I am sure that she did not have a close family.

Mikoto-san asked what her relationship was with me.

I don’t really know that either.

But maybe I should take the place of Mikoto-san’s family, just for now.

I had a feeling that she wanted me to do so.

I said.

” Do you want to call me that… again?”

Mikoto-san’s eyes widened and she looked happy.

“Akihara-kun, do you want me to call you Onii-chan? That’s weird.”

“Mikoto-san started it.”

“Okay. If you want me to, Akihara-kun, I will call you Onii-chan just one more time.”

Mikoto-san looked at me and I looked at Mikoto-san.

I felt somewhat embarrassed.

We remained silent for a while.

Finally, perhaps having made up her mind, Mikoto-san opened her mouth.

She smiled softly, her face reddening, and said.

“I’m looking forward to working with you tomorrow, too. Haruto Onii-chan.”