Starting with erotic stories and wood block prints from before the 20th century, Japanese pornography evolved into distinct subcategories. Reflecting Japan's views on sexuality and culture, Japanese pornography delves into a wide spectrum of heterosexual, homosexual, and transgender sexual acts in addition to unique fetishes and paraphilias. In addition to pornographic videos and magazines featuring live actors, there are now categories of pornographic manga and anime (i.e., hentai), and pornographic computer games ( eroge for both PC and game consoles). Animated films are referred to as hentai in English, but in Japan the terms ' adult anime' and ' erotic animation' (or ero anime) are used.

Pornographic films are known as ' adult videos' (AV) in Japan, so Japanese adult videos are ' JAV', referring to the Japanese pornographic film industry. Pornography in Japan has unique characteristics that readily distinguish it from western pornography.