Beelzebub

Picture a school made entirely of delinquents, and Tatsumi Oga reigns as the most violent of them all, which is already a pretty solid setup. Then a baby crawls onto his back and won't let go. That baby happens to be Kaiser de Emperana Beelzebub IV, son of the Demon King, sent to the human world to find someone strong and terrible enough to raise him so he can eventually destroy humanity. Oga, being the worst person at the worst school, apparently fits the bill perfectly. A demon maid named Hilda shows up to explain the situation, and from there it's 60 episodes of Oga trying to either get rid of Baby Beel or reluctantly lean into the whole demon-dad thing while punching his way through rival delinquents and supernatural threats. The comedy here is genuinely funny: the show gets a lot of mileage out of the contrast between brutal school brawls and the absurdity of a terrifying fighter doing childcare. Oga's power is directly tied to Baby Beel's demonic energy, so the stronger his bond with the kid, the harder he hits, which is a neat twist on the usual shounen power escalation. If you liked the chaotic comedy of Gintama or the delinquent energy of Great Teacher Onizuka, this hits a similar nerve. Fans of Katekyō Hitman Reborn will also recognize the "baby grants power to reluctant fighter" formula, though Beelzebub leans harder into the comedy side. It's a good time if you want action with real laughs baked in.