One day Takumi, a university student who writes erotic novels on the side, is approached by his beautiful classmate Otoha Nodoka. She says that she's a fan of his work, then suddenly shows him a video of herself masturbating and asks him to help her become successful as an amateur porn star
Ahh I see where this is going.. Diabel sold himself to the devil.. And he's making her hate him...by saying lies .. Because he's gonna disappear soon. .. That's my guess