Dr. Takao Ameku is the 27-year-old director of the Department of Investigative Pathology at Tenikai General Hospital, though her youthful, cat-like appearance often leads people to mistake her for a high school student. She is a genius doctor with superhuman memory and observational skills, capable of diagnosing complex diseases from the briefest glance and even reading personal information about strangers like a modern-day Sherlock Holmes. However, she is eccentric, lacks empathy, and is driven by an insatiable love for solving mysteries, which frequently leads her to meddle in cases far beyond standard medical diagnostics. Her reluctant assistant is Yu Takanashi, a practical young man often assigned the role of a Watson to her Holmes, who gets dragged along as she unravels the truth behind inexplicable illnesses and deaths.

The setting is the rooftop of the Tenikai General Hospital, where the small Investigative Pathology department collects patients deemed difficult to treat by other doctors. From this base, Dr. Ameku also tackles mysterious deaths and murder cases that even the police find too complex to handle. Written by Mikito Chinen, a practicing physician, the series aims for medical accuracy while blending traditional detective fiction with hospital drama. The manga adaptation, illustrated by Hiroki Ohara, was serialized in Monthly Comic @Bunch from April 2016 to March 2018 and is collected in four volumes.

Early narrative arcs showcase Dr. Ameku's brilliance and her specific character flaws. In an episode called Invisible Fetus, her overconfidence in her own observational leads to a significant misdiagnosis, forcing her to confront the limits of her abilities. Another case, referred to as Bubble, demonstrates her high-level strategic thinking; she not only diagnoses a patient through momentary observation but simultaneously identifies a culprit and manipulates the situation to trap them. Throughout these events, the story balances action and medical mystery with moments of comedy, largely derived from Ameku's disregard for social norms and her interactions with the more grounded staff around her.