Solitary island in the distant sea. The ship taken by the class trip damages seriously, schoolgirl Kisaragi Rei and Ouma Shiho, “Sexual excitement” it did and it turned into the masturbation madness. By the story of mysterious beautiful woman Ichijou with the medical knowledge, it seems to be the infection symptom of a certain special virus. And to suppress the progress of the mortal virus, it is said that it is necessary to take man’s semen into the body very much.