Parents, half brother and cousin.
They are ok. For the story, they are a quite bland troupe... Ex pro tennis player-perverted father, americanized naggy-with-her-husband mother, yamato nadeshiko cousin. And then there is the mystery of the half brother... who looks identical to Ryoma... and Ryoma wasn't in contact for long time and is not able to remember... and some other garbage that only Konomi sensei can pull off his ass in his incoherent universe and story.
I try to not give much thought into the idea of his father sneaking with his porn all day, publicly and messing with my bra size, or else.
I got used to it.
Anyway, apples don't fall far from the tree: Ryoma inherited his cheekiness...
Had some contact with them in an official game. It was fine. They feel like in-laws.