Fourteen-year-old Iruma Suzuki has just been abandoned and sold to a demon by his irresponsible parents! Surprisingly, the next thing he knows he's living with the demon who has adopted him as his new grandson and has been transferred into a school in the Netherworld where his new demon grandfather works as the principal. Thus begins the cowardly Iruma-kun's extraordinary school life among the otherworldly as he faces his true self, takes on challenges, and rises to become someone great.

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!

Human boy Suzuki Iruma becomes "grandson" to the great demon Sullivan and begins attending demon school where "Grandpa" serves as chairman. Winning friends -- and rising in demon rank, too -- Iruma thrives in his new environment, overcoming the harrowing ordeals thrown his way! In the new season, further challenges await... it's harvest season, and time for the annual test where students wade into the expansive and extremely dangerous (!) jungle to compete for food!! Classmates become rivals, and what erupts is a gargantuan battle of brawn and wits?