Mc and his sister, Nana, used to lives by themselves after they lost their parents in an accident. His little sister is everthing to him. But he have a huge regret. In the past, Nana experienced terrible life and traumatized because she became a victim of sexual assault by group of rich men. Mc who drowned in despair wanted to revenge upon those dirty old man. He becomes a teacher in a school where the daughter of the those dirty men study. He approaches his target as a good teacher so he can earn their trust until the judgement day has come. He invited the rich men’s daughter to a remote villa for a supplementary class. He set up a secret room so they won’t be able to escape from his plan.