Ayana Kirisaki, the hentai bishoujo who loves sex. Born of tentacle origin she will go on fulfill the legend of her species, and fight as an Orga Knight in defense of her galaxy and tentacle planet. But today... Ayana has no idea of the future. She's just an ordinary schoolgirl living an ordinary life in Neo Tokyo. A new virus breaks out, turning everyone into sexual weirdos. This so-called "otaku flu" sweeps the city. To stop the epidemic from further spread Neo Tokyo is quarantined. Otaku flu victims are limited to otaku schools in the otaku district. It's dubbed Otaku City, a place full of diseased freaks. Ayana finds out on the news that sex with these otaku produces a more intense orgasm than anything. "I'm going to Otaku City to screw until there's not a virgin left among them!" She transfers to the new school. From the first day, not just her classmates but the teachers all cum at the nympho. Ayana is lost in a sea of constant sex...