Kyōichirō Kazamatsuri is a police inspector in the Kunitachi Police Department and the heir to Kazamatsuri Motors, a major automobile company. He comes from a wealthy family and frequently flaunts his status, arriving at crime scenes in expensive sports cars and wearing extravagant pure-white suits that set him apart from typical detectives. Despite his high rank, Kazamatsuri possesses almost no deductive ability. His investigative approach is largely superficial, and his conclusions are often illogical, leading investigations into dead ends. He is self-absorbed and unaware of his incompetence, viewing himself as a capable detective.

Kazamatsuri serves as the direct superior of Reiko Hosho, a rookie detective who secretly comes from an even wealthier family. He remains completely unaware of Reiko’s true background. His role in the story is primarily that of a comedic foil: his misplaced confidence and poor judgment create humor, especially when contrasted with the actual deductive work done by Reiko and her butler, Kageyama. Kageyama, in particular, often subtly mocks Kazamatsuri, but Kazamatsuri is too self-absorbed to notice.

In terms of development, Kazamatsuri remains a static character throughout the series. He does not undergo any meaningful change in personality or skill. His motivations center on maintaining an image of authority and wealth, but he lacks the competence to back it up. Notable abilities include his flair for dramatic entrances and his talent for making incorrect deductions with confidence. His character highlights the disconnect between inherited wealth and genuine talent, serving as a constant source of lighthearted frustration for those around him.