For a game with avoidable ntr its realy need rebalance. For example, p.e. To protect Rei you need either keep grow stamina and pair with her or sacrifice Anna. And even if you do last one Rei still be corrupted while you grow Anna love. Yes, you hew few initial days, but not enough and you most likely use tham for pump stamina. And in the future you have to keep staying in class B to stop Vick, but its block several characters. Somewhat fair, but if you can keep all 3 main girls for yourself in same time, why such limitations ? And what's a point of Anna's bottle now. When we got chance to date her, you can use it for protect both girls and have extra time, for now Anna just scapegoat with no point to protect expect pity.
Btw, Rin starts go to hotel without extra corruption, bug ? And her and Kenta after MC without context, blackmail or just wh0re ?