rui is an employee of the crossdressing bar owned by kanato, a former av star. I BELIEVE it's mostly a male crossdressing bar (in ch9 natori also crossdresses as a woman) so rui is implied to be male and uses he/him in english translation (idk abt japanese)
idk if this was obvious to everyone else, but I think the writer is implying that Yanagi's uncle tried to sexually him when he was younger. the shadow man with the dress shirt and tie... Yanagi doesn't remember the details, but it kind of explains why his aunt and uncle were constantly arguing, and his uncle doesn't even show up in the latter chapters. did they get divorced?