: 変態 【へんたい】 (n, sexual perversion, sexual pervert; adj, sexually perverted)
In Japanese "Hentai" refers strictly to sexual perversion. However in North America this word has been adopted and is used to refer to pornographic Anime. In Japan pornographic Anime is called Poruno Anime (Japanese prnounciation of "Porno") or Ero (From erotic/eros). Some pornographic Anime is also referred to as bishoujo, based on the character design style of the female characters, however not all bishoujo is pornographic; Sailor Moon, Sakura Wars and Meiking are all bishoujo, but only Meiking is pornographic.
Because the word hentai is derogatory, fans of Ero do not approve of its use to refer to pornographic Anime.
Women and girls will often call a man "Hentai" when they believe that he has purposefully done something to them, or thought of them, in a sexual manner that they do not approve of. In Anime this is often used for comedic purposes when a male character accidentally finds himself in a position that embarrasses a female character. This gag is very common in Anime such as Ranma 1/2, Love Hina or City Hunter, where the unlucky male is often subjected to extreme pain (possibly involving a baka-hammer) after being called "Hentai."
