Endro!

On the magical island of Naral, the endless cycle of heroes and demon lords continues. Each era brings a new Demon Lord to threaten the land, and with it, a Hero destined to stop them. The current Hero, Juulia "Yusha" Charldetto, is on the verge of victory with her trusted party: the dependable priest Seiran "Seira" Élénoir, the mysterious mage Meiza "Mei" Endust, and the excitable warrior Fai Fai. During their final battle against the Demon Lord, the group attempts a dangerous spell to banish their foe through time. But the magic misfires, hurling Yusha and her friends back to their younger days-before they became heroes, before they even graduated as adventurers. Stripped of their memories of the future, they set out once more to form the Hero's Party and face the Demon Lord. Unbeknownst to them, the Demon Lord was also flung back in time, retaining all her memories. Now trapped in the body of a child, she adopts the name Mao and slips into the adventurers' school as a teacher, plotting to eliminate Yusha before she can fulfill her destiny. And so, Yusha and her friends embark on their quest, unaware that the Demon Lord they seek walks among them.