The thought police, also called the Special Higher Police (Tokubetsu koto keisatsu, abbreviated Tokko), was a police force established to investigate and punish “dangerous” political groups and ideologies. In 1910, there was a conspiracy plot to assassinate Emperor Meiji, and the thought police was formed in 1911 to stop similar situations from happening in the future. Initially, the Tokko focused on communists, anarchists, socialists, and feminists, but in 1925 a law was passed that greatly empowered the organization, allowing it to work overseas in areas with high densities of Japanese (e.g., London, Berlin, Shanghai). In its first 25 years of existence, the organization arrested nearly 60,000 people, 5,000 of whom were brought to trial, with half of those being sentenced to death. Shiina Rinzo and other Japanese authors with communist ties were among those arrested, some multiple times. The thought police was disbanded by order of the American Occupation authorities in 1945.
Historical dictionary of modern Japanese literature and theater. J. Scott Miller. 2009.