I want you to raise the next hero" — These final words of the former hero, Yukina, were received by none other than her longtime nemesis, the Demon King Melc. Time passed, and Melc, reincarnated as a human, lived a quiet life raising disciples in a remote countryside village. Having sent his last two pupils, Ally and Mileno, to the hero training institution "Arcrest Hero Academy" in the royal capital, he intended to spend his remaining years as a mortal... when suddenly, Melc is summoned to serve as an instructor at the very same Hero Academy. Will he truly be able to raise a hero who surpasses Yukina!? The tale of the former Demon King raising heroes begins here!