Kimiyasu Sakurai is a detective within the First Investigation Division of the Tokyo Metropolitan Police Department, holding the rank of Assistant Inspector or Lieutenant. A notable aspect of his character is that he is a great admirer of the fictional detective Columbo, and he deliberately imitates that character's distinct style of dress. His primary role in the story is to collaborate with the brilliant but unconventional diagnostician Takao Ameku during criminal investigations. He holds Takao Ameku's deductive abilities in very high regard and chooses to cooperate discreetly from behind the scenes, valuing her unique perspective on cases that intersect with the medical field. In terms of his background and connections, Kimiyasu Sakurai also appears in other works by the author Mikito Chinen, which establishes him as a character who exists within a broader shared universe. He has ties to the staff of the Miki Clinic, a medical facility where Tsubasa Ameku, the highly skilled psychiatrist and brother of both Mazuru Ameku and Takao Ameku, works.