Five hundred years after the Demon King Gigue was defeated by the female hero Mia, the descendants of the hero were arrogant. Aru, the bottom adventurer, is deceived by such a brave man and gets a cursed sword. However, the sword caused Aru to regain all the power and memory of the Demon King Gigue. As a reincarnation of the Demon King Gigue, Aru embarks on a journey to wipe out the rotten hero.