Fourth season of . 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?