The era when the reproduction of the body became allowed by enactment of the cloning method. Rich people all made copies of their own, but there was always a need for someone to maintain beneath the unconscious spare body's neck. There is a special occupation "Rent Head <face rental store>" which allows you to freely detach your head there.
Konoe A (Connie Answer / ♂) is a student 's rent head who continues detective mental by borrowing the client of Yasuda Q (Yasuda queue / ♀) which is a client. In order to find his original body that he lost eight years ago, he was stabbing himself in the affair of the rent head.