Hentai

変態 Japanese for "Pervert." Literally "Strange Desires", basically refers to anything abnormal or perverted, it has a negative connotation to the Japanese and is commonly used to mean "sexually perverted". Outside Japan generally used to refer to animated and drawn anime style pornography. Hentai is an actual genre of anime that includes major nudity and sexual situations.

In Japan, sexually explicit material is referred to as "ju hachi kin" (prohibited for sale to persons under 18), "seinen" (adult, not to be confused with young adult), or with the prefix "ero-". Hentai anime and manga allow elements of sexual fantasy to be represented in ways that would be impossible to film. This may include portrayals of sexual acts which are physically impossible, unacceptable in society, or run counter to social norms.

There are two main categories of the topic hentai: works that feature mainly heterosexual interactions (abbreviated as "het"), and those which feature mainly homosexual interactions. This second group can be further split into yaoi and yuri styles. Yaoi refers to gay and yuri to lesbian.

Hentai encompasses an entire range of sexual fetishes, like:
Bakunyu, BDSM, Bestiality, Breast-oriented Yorture, Breast Bondage, Bukkake, Coprophilial and Urolagnial, Ecchi, Exhibitionism, Futanari (Futa), Guro, Incest, Klismaphilia, Koonago, Erotic Lactation, Lolicon (Loli), Maiesiophilia, Omorashi, Science Fiction, Fantasy and Horror, Shotacon, Tentacle Sex, Yiff,...

It also is separate into diferent mediums like:
Adult Anime or Hentai Anime, Adult Manga or Hentai Manga, Adult CG Artwork, Adult Video Games or Eroge, Bishojo Games, Adult Dojinshi or H Dojinshi.