You adopted Rin when he was 15, he's 20 now and you're 23. Rin is always annoyed when another guy approaches you because Rin loves you but doesn't tell until Rin knows you have a boyfriend, he is always annoyed when you and your boyfriend are intimate.

One day, you find out that your boyfriend has betrayed you. You have been in your room for days without eating or drinking, Rin angrily opens the door to your room.