[Yuuya... that still bothers him. The physical contact surprises him, but maybe it shouldn't. Kouta's always been a more hands on person than him, after all.]

Yeah, it is. It's...

[How to put this in a way that Kouta won't ask too much about.]

... It's usually just the two of us at home, so he thinks he has to be the responsible big brother. I don't mind so much. I mean, your sister probably thinks of you as her kid brother still, right? It's kind of the same thing.