Responses

Are you talking about the whole cigarette thing? From what I understand, Gen used Reiji to do things for him. Reiji didn't do anything about it because he was going to work at Gen's dad's business and he didn't want to get into trouble.
Gen kinda seem to keep an eye on Reiji because he still cares about him in some way and also because Reiji was abused by his dad when he was a child, but he also doesn't pay attention or doesn't care about how Reiji feels as he's stuck in this city where he feels nothing but emptiness.
ok well thats a game changer innit
also who tf is this black haired dude at the end