I can't believe this is only chapter 4, I'd say very good chapter, I thought it was just going to be the two girls going to the arcade at the same time, maybe the "shy" twin following the sister, but no we got some interesting insight on all three characters.
He found the wrong one but he was still positively assertive he didn't get to say "I like you too" but given his actions, it wasn't needed.
I am re-reading the chapters, his assertiveness is even more special because we see at the very first one how he is afraid of sticking out, "the nail that sticks out will get hammered down" 13/42 chap 1. This is after he is chastisized for not trying harder on his exams.
Again in the second chapter, the problem of sticking out. with the teacher Tachibana sensei.
Maybe this series will be a fight against that, against the expectation of this micro-cosm.