High School DxD

High School DxD is an ecchi harem action-comedy anime (adapted from light novels) that's famously known for its heavy fanservice, supernatural battles, and over-the-top humor.

Quick synopsis:

The story follows Issei Hyodo, a hopelessly perverted high school student at Kuoh Academy whose biggest dream is to build a harem and become "Harem King." His life takes a wild turn when his very first date ends with the girl (a fallen angel) straight-up killing him.

As he's dying, he summons Rias Gremory, the stunning crimson-haired beauty and most popular girl at school—who turns out to be a powerful high-class devil. She revives him as a devil and reincarnates him into her service using an "Evil Piece" system (like chess pieces for devils).

From there, Issei joins Rias's peerage (her group of devil servants) in the Occult Research Club, which is secretly a front for her devil activities. He gets dragged into conflicts between devils, fallen angels, and angels, while gaining increasingly ridiculous powers (including a sacred gear tied to a legendary dragon), fighting enemies, making contracts, and—most importantly—surrounding himself with beautiful girls who gradually join his growing harem.

The series mixes high-stakes supernatural battles, Rating Games (devil chess-style tournaments), school life comedy, and a ton of ecchi moments (boobs are practically a plot point). It starts very heavy on the fanservice and harem antics but gradually builds more serious action and power-scaling as the story progresses through multiple seasons.

It's basically "pervert gets isekai'd into devil society and lives the harem dream while punching angels and dragons."

If you're into ecchi + supernatural action + harem tropes, it's one of the genre kings. If fanservice isn't your thing, it might be overwhelming 😅