Hentai is defined differently in English. The Oxford Dictionary Online defines it as 'a subgenre of the Japanese genres of manga and anime, characterized by overtly sexualized characters and sexually explicit images and plots.' The origin of the word in English is unknown, but AnimeNation's John Oppliger points to the early 1990s, when a Dirty Pair erotic doujinshi (self-published work) titled H-Bomb was released, and when many websites sold access to images culled from Japanese erotic visual novels and games.
The earliest English use of the term traces back to the boards with a 1990 post concerning Happosai of Ranma ½ and the first discussion of the meaning in 1991.
