Kyo Kara Maoh! - God (?) Save Our King!

When Yuri Shibuya's head gets shoved into a toilet by bullies, he finds a portal to another world instead of water — standard Tuesday. He lands in a medieval fantasy kingdom and is immediately told he's the new Demon King — not because he asked, not because he trained for years, but because the magic just decided he was the guy. He's a regular Japanese teenager who plays baseball and has a strong sense of fairness, and now he has to run a kingdom full of demons while navigating political tensions, sword-wielding nobles, and an accidental engagement he definitely did not consent to. The show leans hard into that last part for comedy, and it works. The humor comes from cultural misunderstandings and Yuri repeatedly trying to apply his modern, pacifist sensibilities to a world that resolves conflicts by fighting. It's warm and comedic without being toothless — there's actual heart in how Yuri approaches leadership and his relationships with the people around him. If you liked Fushigi Yugi or Juuni Kokuki and want something with a lighter, more comedic touch, this hits that same isekai-political-drama space but doesn't take itself too seriously. It's a long one at 78 episodes, so it takes its time building the world and the cast, but fans of character-driven shoujo fantasy with a comedic backbone tend to find that worth it.