In the law enforcement system in Japan, prefectural police are prefecture-level law enforcement agencies responsible for policing, law enforcement, and public security within their respective prefectures of Japan. They are mostly under the central oversight and control of the National Police Agency.

As of 2017, the total strength of the prefectural police is approximately 260,400. Japanese police force helicopters do not share the flamboyant colour schemes of their counterparts in prefectural fire and disaster relief units. Aside from the titling to indicate by which prefecture they are operated and individual aircraft names, police helicopters are clad in variations of a uniform blue “uniform” and wrapped in a high-visibility dayglo stripe. Standard markings consist of a Japanese national flag on either side of the engine housing and a floral Order of the Rising Sun marking, which in gold forms part of the National Police Agency’s badge, wherever space will allow on either side of the tail or fuselage. The Niigata force seems alone in having applied local badges to its aircraft. 

For the most comprehensive information on Japanese Prefectural Police aviation (and all contemporary Japanese military aviation), see: https://www.j-hangarspace.jp/police-air-units