Movie
Description
Ninzaburou Shiratori is an inspector in the Tokyo Metropolitan Police Department's First Division, working under Inspector Megure. He comes from a wealthy family, and his upbringing has given him a refined set of interests, including architecture, cooking, and collecting wine, with a particular fondness for Romane Conti. His background and tastes often make him appear more conceited than his colleagues, though this arrogance has softened over time.

Shiratori's decision to become a police officer instead of a lawyer stems from a childhood encounter. As a young boy studying to be a lawyer, he witnessed a girl confronting two juveniles attempting to steal manga from a bookstore. When the thieves pushed her down, Shiratori stepped in and recited the legal provisions for theft, scaring them off. The girl bought him a drink and made a sakura petal pattern from a straw wrapper, explaining that the sakura is the symbol of courage for the Japanese police, just as he had acted with courage. Inspired by her words and the connection to the police badge, Shiratori abandoned his law aspirations and joined the force, carrying the memory of that girl as his childhood love.

For a long time, Shiratori believed that fellow officer Miwako Sato was that girl, leading him to pursue her romantically and view colleague Wataru Takagi as a rival. He would often try to impress Sato and even led a secret group of officers to protect her from other suitors. However, Sato ultimately chose Takagi, leaving Shiratori crushed but still unable to let go of his mistaken belief. Later, through a series of events involving the Detective Boys, he discovered that the true girl from his childhood was Sumiko Kobayashi, a teacher at Teitan Elementary School. Once this realization set in, his fixation on Sato dissolved, and he began a genuine, mutual relationship with Kobayashi. This relationship also helped curb his arrogance, making him more modest and friendly, especially toward Conan Edogawa, Ai Haibara, and the other children.

As a police officer, Shiratori is competent and calm, often keeping his composure on cases more effectively than Takagi or Sato. He is observant and knowledgeable, particularly in matters related to his upper-class interests, such as wine-related cases. While he initially dismissed Conan's input, he has come to take notice when Conan points out something significant, though he remains less openly reliant on the boy's intelligence than some of his peers. In the film Case Closed: Zero the Enforcer, Shiratori appears as a supporting member of the police force, contributing to the broader investigation alongside Megure and others as the story unfolds around a terrorist conspiracy and the arrest of Kogoro Mouri.

Over the course of the series, Shiratori undergoes notable personal growth. He moves from being a cocky, love-obsessed officer willing to misuse his authority for romantic gain to a more settled and genuinely caring partner. His development is closely tied to his relationship with Kobayashi, which brings out a more protective and gentlemanly side of his character. He remains a steady and reliable inspector, valued for his knowledge and composure, even as his earlier vanity gives way to a more balanced personality.