The Misfit of Demon King Academy

The Misfit of Demon King Academy: History's Strongest Demon King Reincarnates and Goes to School with His Descendants, Maou Gakuin no Futekigousha: Shijou Saikyou no Maou no Shiso, Tensei Shite Shison-tachi no Gakkou e Kayou, Maou Gakuin no Futekigousha