Mikoto Misumi is a pathologist at UDI (Unnatural Death Investigation) Lab. She can't stand neglecting unnatural deaths and believes there must be a truth behind the deaths. Team members that work with her are autopsy doctor Kai Nakado, recorder Rokuro Kube, clinical test technologist Yuko Shoji and UDI director Yasuo Kamikura. They work on unnatural death cases and try to reveal the truth behind the deaths.