Endro~!

Sinopsis

In the Kingdom of Lapanesta, the hero Yulia "Yusha" Chardiet and her companions successfully defeat the Demon Lord. However, their sealing spell goes awry, inadvertently sending the Demon Lord back in time to an era before Yusha became a hero. Transformed into a small girl, the Demon Lord, now named Mao, takes on a teaching position at Yusha's Adventure School. Her new goal is to ensure Yusha never achieves hero status, thereby preventing her own future defeat.