Do Tae Rang must keep things nice and clean all the time. He won't allow any stains. He happens to work at a cleaning service for crime scenes. The service is run by Mo An Na and Do Tae Rang is the company's only employee. While they clean up a criminal site, Mo An Na and Do Tae Rang uncover a truth.

The story of a detective who lost his partner to a crime caused by a juvenile offender. The drama examines the loopholes and ambivalence of the justice system when it comes to juvenile crimes.