From the back of the PDF:
Orgasms, kisses and caresses. Tears and saliva and blood. Muscles straining, blood pulsing through engorged veins, bodies slamming together with unbridled, inhuman passion. Mouths opened in ecstasy or lips drawn back in agony.
Other Genres may explore sex, flirt with pleasure, toy with relationships and encompass themes of love, but Hentai is somehow different. Hentai explores the visceral, organic reality of sexuality, embracing and exaggerating the biology of sex itself to shock, to arouse, to tell a story. Hentai reminds viewers that we are meat machines, and revels in spurting fluids and heaving flesh.
Black Tokyo focuses on one particular sub-genre of hentai: supernatural horror and bondage. With visually spectacular demon lords, stunning sexual action scenes, virginal heroines, hyper-sexualized magic rituals and psi-talents, and cunning moodern demon-slayers, horror hentai makes the most 'gamable' background for a hentai flavored setting.