Hentai (変 态 or へんたい?) Is a video game, anime, or manga featuring sex scenes or pornography. Hentai is a Japanese slang word used to insult someone who is behaving in a strange and suggestive naughty nasty.
In Japan, Japanese people rarely mention hentai for anime, manga, or video game porn. They use the term ecchi. In addition there are several other more specific terms such as ju hachi kin (18 禁 / 18-kin; for 18 years and over), with permission manga (manga for adults), ero anime (エロ アニメ; stands for erotic anime), or ero manga (エロ 漫画; stands for erotic manga).