Police system of Japan

Law enforcement in Japan is provided by the Prefectural Police under the oversight of the National Police Agency or NPA. The NPA is administered by the National Public Safety Commission, thus ensuring that Japan's police are an apolitical body and free of direct central government executive control. They are checked by an independent judiciary and monitored by a free and active press.

The Japanese government established a European-style civil police system in 1874, under the centralized control of the Police Bureau within the Home Ministry, to put down internal disturbances and maintain order during the Meiji Restoration. By the 1880s, the police had developed into a nationwide instrument of government control, providing support for local leaders and enforcing public morality. They acted as general civil administrators, implementing official policies and thereby facilitating unification and modernization. In rural areas especially, the police had great authority and were accorded the same mixture of fear and respect as the village head. Their increasing involvement in political affairs was one of the foundations of the authoritarian state in Japan in the first half of the twentieth century.

The centralized police system steadily acquired responsibilities, until it controlled almost all aspects of daily life, including fire prevention and mediation of labor disputes. The system regulated public health, business, factories, and construction, and it issued permits and licenses. The Peace Preservation Law of 1925 gave police the authority to arrest people for "wrong thoughts". Special Higher Police (Tokko) were created to regulate the content of motion pictures, political meetings, and election campaigns. The Imperial Japanese Army's military police (Kempeitai) and the Imperial Japanese Navy's Tokkeitai, operating under their respective services and the justice and home ministries aided the civilian police in limiting proscribed political activity. After the Manchurian Incident of 1931, military police assumed greater authority, leading to friction with their civilian counterparts. After 1937 police directed business activities for the war effort, mobilized labor, and controlled transportation.

...
Wikipedia