"I want you to raise the next hero" — These were the last words spoken by the former hero, Yukina, which were heard by none other than her long-time rival, the Demon King Melc. As time went by, Melc, who has been reincarnated as a human, led a peaceful existence teaching disciples in a secluded rural village. After sending his last two students, Ally and Mileno, to the hero training institution "Arcrest Hero Academy" located in the royal capital, he planned to spend his remaining days as a mortal... when unexpectedly, Melc is called upon to take on the role of an instructor at the very same Hero Academy. Can he genuinely nurture a hero that surpasses Yukina!? The story of the former Demon King raising heroes begins now!