Mayu Mitsui

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.

It is difficult to stand out at a Ginza club where every hostess wants to be number one. It is competitive. One of them is a virgin and also just eighteen years old. She wants to become the number one hostess to help pay the bills for her family. She advertises herself as 'virginity for sale.' It is an auction and the prize goes to the highest bidder. She doesn't have hostess skills however. The club's manager was the number one hostess in all of Ginza and helps the younger woman.

Mitsuki and Yuya become stepsister and stepbrother because of their parents' marriage. Mitsuki can't get along with her new family and Yuya doesn't know how to approach his new stepsister. One day, Mitsuki becomes possessed by the spirit of Hiyori. Hiyori likes Yuya and believes Yuya can help her get to heaven. Hiyori places a leather chastity belt upon on Mitsuki and a plan takes place to help send Hiyori to heaven.