Concerning the historical development, during the Edo period - we are talking about the years 1600 - 1868 here, the Tokugawa Shogunate ( the form of those days governing the country ) developed elaborate police system based on town magistrates who held samurai status and served as chiefs of police, prosecutors and criminal judges. The system was extended by citizens ´s groups such as five-family associations ( gonin gumi ) . These groups were composed of neighbours, collectively liable to the government for the activities of their membership.
After the Meiji Restoration in 1868, the main change in the whole Japanese history, the Home Ministry was established in 1873. With jurisdiction over the Police Bureau, it effectively controlled the police. This new, centralized police system had wide-ranging responsibilities, includng the authority to issue ordinances and handle quasi-judicial functions. It also regulated public health, factories, constructions, businesses and issued permits, licenses and orders.
In 1911 the Special Higher Police was established to help control proscribed political activities. Later in 1928 it was strengthened with the introduction of the Peace Preservation Law. When the Sino-Japanese War began in 1937, the police were given the added responsibilities of regulating business activities for the war efforts, mobilizing labour and controlling transportatioon. Also regulation of publications, motion pictures, political meetings, and election campaigns came under police direction.
After World War II, Japan as a defeated country was under strong pressure and influence mainly from the U.S., on all branches of life, including the police system.