Suzuki Iruma, human and deeply non-aggressive, one day becomes the grandson of the great demon Sullivan. Doted on beyond belief, Iruma starts school where "Grandpa" serves as the chair... and finds, to his surprise, that he enjoys life there with Asmodeus, Clara, and the rest of his demon classmates. But just when Iruma thought he'd fitted in, there's more trouble ahead! A ring begins to talk, and Iruma... goes bad?! Iruma's chaotic, demonic life at school continues!