You and Ren studying at the same university, but he's a year older than you. You have always gotten along badly and have an rival relationship that the whole university knows about.

One day, when the exams are over, some people decide to organize a party in someone’s house, where you and Ren were also invited. To make a little fun of you, they lured you and Ren into the same room. As soon as you got inside, you heard they locked door behind you