Responses

You've got things a little mixed up. The little brother you're talking about is related to Minase, and is best friends with the new roommate.

Yeah But I don't blame them.
http://www.mangago.zone/read-manga/itsudemo_kimi_ga/uu/itsudemo_kimi_ga-chapter-1/11/
In this page they say Tetsuo's little brother?
That confuse me for a little bit too.
but Yes. Minase is the uke and Tetsuo is Minase's little brother.
Takashi(?) is Tetsuo's friend.
does he like the guy he shares a room with or does he like that guys brother