Hentai is not a monolithic genre; it boasts a variety of subgenres catering to diverse tastes and fetishes. From BDSM to fantasy-themed narratives involving mythical creatures, hentai explores themes that range from the conventional to the highly imaginative.

Two primary formats dominate hentai: manga (comics) anime 18+ and anime (animated series). Manga offers detailed illustrations and complex storylines, while anime provides dynamic visual storytelling. Additionally, doujinshi—fan-created comics—play a pivotal role in expanding the genre's reach.

The genre also intersects with other anime genres like science fiction and fantasy, creating hybrid narratives that appeal to niche audiences. This diversity has contributed to its enduring popularity despite societal stigmas.