The series takes place at Ten’ikai General Hospital, specifically in its “Supervisory Department of Diagnostic Pathology” (or the general diagnostics / investigative pathology division). This department handles the kinds of cases other hospital departments can’t figure out — mysterious illnesses, strange deaths, and sometimes cases that border on crime or the supernatural. The central figure is Takao Ameku – a brilliant, highly‑unconventional doctor whose diagnostic ability rivals that of a detective. She’s supported by her colleague Yu Takanashi, among others, as they tackle medical mysteries that go beyond typical hospital fare.