Kazunobu Chiba serves as a police detective in the Tokyo Metropolitan Police Department’s Second Violent Crimes Investigative Division, Section 3, routinely collaborating with Inspector Juzo Megure and Detective Wataru Takagi. His responsibilities include evidence collection, interviewing non-suspects, and briefing superiors. Overweight in build, his physique occasionally becomes a source of humor. A Teitan Elementary School alumnus, he participated in the broadcasting committee and co-created the tokusatsu film *Kamen Baiya*. During this time, he formed a close bond with Naeko Miike, penning her a love letter before her family relocated. Miscommunication obscured their mutual affection, though their paths later realigned: Naeko joined the police as a traffic officer after Chiba cited her for a violation, stressing legal accountability. Years later, he initially failed to recognize her upon her transfer to Tokyo.
Chiba adheres unwaveringly to legal protocols, even in personal matters, yet balances this rigidity with a playful demeanor. He snacks frequently, favors tokusatsu series like *Kamen Yaiba*, and decorates his apartment with genre memorabilia. His habit of rewinding VHS tapes traces back to his brother’s employment at a video rental store. Professionally, he aids colleagues without hesitation—supporting Takagi’s courtship of Miwako Sato, abstaining from plots against their relationship, and contributing to cases ranging from reconciling witness discrepancies to solving a murder tied to his roommate.
His backstory intertwines with his duties when he revisits Teitan Elementary with the Detective Boys to retrieve Naeko’s hidden response to his childhood letter, ingeniously revealed by sweat-activated ink on a VHS tape. Though her absence at a reunion initially disheartened him, their eventual reunion as colleagues reaffirmed their bond. Through stakeouts, procedural insights, and team engagements, Chiba evolves from a peripheral figure to a steadfast, reliable presence within the unit, his loyalty and ethical resolve remaining unwavering.