Karin, a sex detective, and Nana, an assistant, have protected the peace of Shimbashi based in a Chinese-style oil beauty salon. In the city, a mysterious incident occurs in which women disappear one after another, but Karin is not so absorbed in having sex with the New York Police Department Kasumi. Nana aims to solve the case with a newcomer China Girl Hachi and pseudo-sex detectives who are a reserve army of sex detectives. As the investigation continues, the shadow of a male office worker who is envious of his female boss, as well as the super-male and female criminal association ADAM, begins to flicker.

Horigai spends her boring days waiting to graduate from college. As she hangs out with friends, she begins to realize the violence and sorrow behind their ordinary lives.