Misumi Mikoto is a medical examiner with a private lab, UDI, which is committed to finding the truth behind unnatural deaths through autopsy. Working with Mikoto are Nakado Kei, also an ME, Kube Rokuro, a recording assistant, Shoji Yuko, a lab technician, etc.
Nakado Kei is an eccentric man with rich clinical experience. Due to different philosophies of justice and law, he and Mikoto seldom see eye to eye. In fact, Nakado has been keeping a secret. His girlfriend died in a tragic "accident". But faint traces convince him that a serial killer took her life. Despite all the gossip against him, Nakado sticks with UDI to find his girlfriend's murderer.