Demon King Daimao

An orphan named Akuto Sai has one goal: become a high priest and make the world a better place. He enrolls at Constant Magic Academy, befriends Junko Hattori, a noble ninja clan member: on the way there, and they both pledge to change society for the better. Then he walks through the school gates and a prophecy announces he's destined to become the Demon King. So much for good intentions. Suddenly the entire student body is terrified of him, Junko doesn't know whether to trust or fight him, and every new character who shows up has their own agenda about what to do with the future Demon King, but from worshipping him to trying to kill him. Akuto just wants to be a decent person, but fate keeps shoving him toward villainy whether he likes it or not. The whole thing runs 12 episodes, so it moves fast. You get magic battles, a harem that assembles around him for wildly different reasons, and a comedic tone that leans pretty heavily into ecchi territory, so fair warning on that front. It's not trying to be deep, but it's an action-packed school fantasy with a romantic comedy engine and a protagonist stuck fighting his own destiny. If you liked The Misfit of Demon King Academy or How Not to Summon a Demon Lord, this hits a similar vibe but came out years earlier. Fans of The Irregular at Magic High School might also find common ground with the overpowered-outcast-at-magic-school setup. It's a fun ride if you're in the right mood for it.