Reiko Houshou, a rookie detective at the National Police Department, is the daughter of the world-famous Houshou Group. Under the guidance of Inspector Kazematsuri, the heir to Kazematsuri Motors, she is struggling through a number of cases.
When she returns to her grand mansion, Reiko changes from her plain pantsuit into a dress and enjoys a dinner. However, whenever she encounters a complicated case, the person she consults about the entire ordeal is her "butler and chauffeur," Kageyama.
"Are your eyes blind, young lady?" — With his sharp, almost abusive tongue, Kageyama points out Reiko's lack of deductive reasoning, but he skillfully unravels the mysteries of the cases with ease.