Head of Tokki division in the Shibuya Precinct. Hates the Tokko division and its members for being so secretive, especially when his fellow officers were murdered by the Phantoms and its human-controlled slaves via Human Face larvae. He is insistent in finding out the reasons why Tokko exists and its agenda, to the cost of possibly losing his job over this. He is especially infuriated when Ranmaru leaves his division for Tokko. He appears to have a daughter named Ruru (most likely a nickname) and is also a womanizer.

Based on various side remarks on Kaoru during certain events in the series, it is apparent that he might have been a gangster in his youth before he decided to reform himself as a police officer. His rough behavior and language also fit the general stereotype of a yakuza.

(Source: Wikipedia)