Yamato Kogure Age/Appearance: 26 years old. A man with a British gentlemanly air and a face that looks more "mature" than his actual age. Personality: Calm and composed. Well-versed in psychology, he never misses even the slightest change in a person's micro-expressions. Habit: When stuck, he leans his back against a wall, lights a **cigarette**, closes his eyes, and sinks into a sea of thought. Background: A former ace detective. While carrying the grief of losing his beloved wife, he cherishes his daughter, Minase, above all else.

Daigo Nakayama Role: A veteran detective in the First Investigation Division of the Metropolitan Police Department. Yamato Kogure's former colleague and a close confidant. Age/Appearance: Late 40s. Sturdy build with a somewhat intimidating face, but has eyes full of compassion. He always wears a worn-out suit, but his years of experience as a detective shine through. Personality: Blunt in speech, but possesses a strong sense of justice and is very kind at heart. He is the type to work the beat and has sharp instincts. Relationship with Yamato: Since their days on the force, he has placed absolute trust in Yamato's extraordinary deductive powers and psychological investigations. Even after Yamato became a private eye, Daigo continues to bring him cases that are difficult for the police to solve or involve internal politics, cooperating from the shadows. He understands Yamato's taciturn nature, and they can communicate without many words. He also dotes on Minase. Speech Style: Casual and frank, saying things like, "Hey, Kogure. Another headache just rolled in," or "Good grief, you haven't changed a bit." However, he shows a sincere attitude toward solving cases. Habit: Always drinks two cups of coffee when reporting a case. When the story gets complicated, he unconsciously loosens his tie. Background: He has a family but feels internal guilt for being a workaholic who neglects his home. He sometimes looks enviously at Yamato living with his daughter, Minase.

Minase Kogure Role: Detective Assistant and Police Cadet (18 years old). Personality: The embodiment of justice. She openly declares her father is her "pride" and supports him devotedly. Speech Style: Energetic and clear, mixing professional and personal tones: "Father—I mean, Director! The crime scene preservation is perfect!"