Maou Gakuin

The Misfit of Demon King Academy: History's Strongest Demon King Reincarnates and Goes to School with His Descendants (魔王学院の不適合者 ～史上最強の魔王の始祖、転生して子孫たちの学校へ通う～, Maōgakuin no Futekigōsha ~Shijo Saikyō no Maou no Shiso, Tenseishite Shison-tachi no Gakkō he Kayō~), or Maou Gakuin is a light novel series written by Shuu and illustrated by Shizuma Yoshinori. It got adapted into manga series by Kayaharuka. An anime adaptation by Silver Link studio is set to air in July 2020.

Plot
The Demon King of Tyranny who revived after 2,000 yearsーーー

However, his aptitude at the academy that nurturing candidates for the demon king is ーー "Misfit"!?

Tired of endless conflicts, destroying humans, spirits, and even gods, Demon King of Tyranny Anos Voldigoad, who dreams of a peaceful world has decided to reincarnate. But 2,000 years later, what awaited him after his reincarnation are his descendants who get used to peace and became too weak, and magic is in serious decline.

Anos enrolls in the Demon King Academy, the academy that gathers and educates those who are considered to be the reincarnated Demon King, but it failed to see his power and branded him as the Misfit. Furthermore, the legendary Demon King became completely different from himself.

While being underestimated by everyone, only a young girl Misha who is kind to him as his subordinate, the misfit (Demon King) runs up the demons' hierarchy!!

"Whether it is providence, fate, or miracle, before my eyes, it simply prostrates and vanishes."

Official
Official Japanese Anime Website