Spica of Sin and Punishment

Hatori is a teacher living a typical life at an ordinary high school. One day, he notices that one of his students, Supika Tsumugi, is being bullied. On his way home in the rain, he finds himself alone with Tsumugi. Hatori tells her, "I'll do something about it," but Tsumugi gently takes his hand and laughs, "Hatori-sensei, you're such a liar." A teacher and a student... two people who shouldn't get too close. Yet, this intriguing girl completely changes the course of Hatori's once-ordinary life...