High School DxD

Meet Issei Hyoudou: a loud, shameless pervert whose biggest ambition is building a harem. Then a pretty girl asks him on a date and stabs him to death. Turns out she's a fallen angel, and his first girlfriend experience is also his last, at least as a human. He gets resurrected by Rias Gremory, a gorgeous senior who also happens to be a high-ranking devil, and suddenly Issei is her servant, dragged into a supernatural world of angels, demons, and ancient power struggles he barely understands. The setting is Kuoh Academy's Occult Research Club, which is less "book club" and more "devil combat squad." From there it's a 12-episode TV series that mixes genuine action with comedy and a lot of fan service, and I mean a lot. But here's the thing: underneath the ecchi stuff, there's actually an interesting power system built around Sacred Gears and Balance Breakers, and the fights have real stakes. The character dynamics in Rias's group are surprisingly fun to watch develop. If you enjoyed Rosario + Vampire or To Love-Ru but wanted more actual combat and mythology woven in, this hits that sweet spot. Sekirei fans will also feel at home with the harem-plus-battles formula. Studio TNK adapted this from the light novels in 2012, and the blend of tones works better than it has any right to. Just maybe don't watch it with your parents in the room.