The Home Ministry was a Cabinet-level ministry established under the Meiji Constitution that managed the internal affairs of Empire of Japan from 1873 to 1947. Its duties included local administration, elections, police, monitoring people, social policy and public works. In 1938, the HM's social policy was detached from itself, then the Ministry of Health and Welfare was established. In 1947, the HM was abolished under the Supreme Commander for the Allied Powers restoration, then its administrative affairs were proceeded to the National Police Agency, the Ministry of Construction, the Ministry of Home Affairs and so on. In 2001, the MOHA was integrated with the Management and Coordination Agency and the Ministry of Posts and Telecommunications, then the Ministry of Public Management, Home affairs, Posts and Telecommunications was established. In 2004, the MPHPT changed its English name into the Ministry of Internal Affairs and Communications. In other words, the MIC is the direct descendant of the HM.

The National Police Agency is the central coordinating law enforcement agency of the Japanese police system. Unlike national police in other countries, the NPA does not have any operational units of its own aside from the Imperial Guard; rather, it is responsible for supervising Japan's 47 prefectural police departments and determining their general standards and policies, though it can command police agencies under it in national emergencies or large-scale disasters. It is under the National Public Safety Commission of the Cabinet Office.