Detective Ozaki is a character who works for the Tokyo district police, operating within the hierarchy of the metropolitan police department. He directly assists and reports to Deputy Chief Kyoko Ishihara, serving as a subordinate officer in her investigative efforts. Ozaki is visually distinctive, characterized by his black hair, facial hair, and a tendency to wear sunglasses while smoking.

His primary role focuses on investigating yakuza activities, with particular attention to organized crime operations affecting Tokyo. Ozaki possesses an intimate knowledge of the criminal underworld, a familiarity that stems from a long-standing professional acquaintance with Tokai, a high-ranking member of the Sagara Alliance yakuza group affiliated with Akira Hojo. Their relationship suggests a history of prior operational contact between the detective and the organized crime figure, which informs their complex professional dynamic. Despite this connection to Tokai and the criminal sphere, Ozaki remains fundamentally committed to his duties as a law enforcement officer, gathering intelligence and evidence while upholding the police hierarchy.