Immoral (2008)

Original title: インモラル　凍える死体

With stalker crimes on the rise in Tokyo, the Meiji Jingu Gaien police department decides to form an all-female Sex Crime Investigation Unit. As the first order of business a member of the theft division is paired with a member of the community safety division. With no experience in brutal crimes, the pair is obviously unprepared for what they're going to face, so two more experienced detectives are soon dispatched to join the them. However, it's already clear to the public and media that this unit is just a gimmick to improve the station's public image.