Female Molester Investigator 3: Shameful Techniques (2000)

Maki is a slutty molester investigator working undercover alongside her senior, Tokiko. Yet behind the scenes, in order to avenge her lover—Detective Yaguchi—she uses her sexual wits to seduce and systematically subject each member of a vicious rape gang to a brutal bloodbath. When she finally comes into contact with her last target, she uncovers an unexpected truth behind the case...