Hentai refers to Anime (Japanese animation), Manga (Japanese comics) or computer games with pornographic artwork. Hentai has a negative connotation to the Japanese and is commonly used to mean sexually perverted.
However, if you have problems with your girlfriend, mother or even your sister, when got caught and trying to explain it, use the picture to explain. It will help to clear things out …. for a while 
[...] Hentai Hentai refers to Anime, Manga or computer games with pornographic artwork. So, be extra careful when your son reads Manga. You don’t want them reading this kind. Don’t let them fool you with this definition. [...]