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.
Iruma and the Misfit Class face their biggest challenge yet as they prepare for the Music Festival, where all thirteen students must reach Rank 4. With a mysterious classmate who cannot afford to stand out, the group must find a way to succeed while keeping his identity hidden. As Iruma's life in the Netherworld grows increasingly eventful, he encounters new demons, unexpected challenges, and opportunities that push him closer to the heart of demon society. From the Music Festival and its aftermath to the Dinner of the Thirteen Crowns and the glamorous Dem-Dol Games, Iruma's friendships, ambitions, and growing reputation continue to shape his extraordinary journey.