Nao works as a clerk at a tax accountant's office. Nakata, the accountant she respects, is a black market accountant who launders money for companies related to organized crime. Nao finds out the secret and tries to expose it, but Nakata and Kita, a member of the yakuza, imprison her and take her chastity. The gangsters give her intensive training so that she will never think of exposing the truth again. In this never-ending hell, Nao 'Nao mind is broken into lust...