Nestled away on the rooftop of Tenikai General Hospital is the unconventional Department of Investigative Pathology headed by the eccentric Dr. Takao Ameku. The tiny department, consisting of Takao and her sole resident Yuu "Kotori" Takanashi, treats complex cases that most other departments within the hospital cannot resolve on their own.

The mystery-obsessed Takao always tries to insert herself into cases that capture her fancy—much to the dismay of her colleagues and the police. Even if her meddling creates more problems for the hospital and those around her, none can deny the brilliance that the young department head exhibits as she weaves a diagnosis together. No matter the specialty, no case is impossible for Takao and a somewhat reluctant Takanashi to solve.