National Archives of Japan (NAJ) was established in July 1971 to preserve important official documents received from Japanese national administrative agencies, provide and exhibit these documents as historical data, and conduct research to build up an efficient reference system of information derived from them. Under the Archives Law implemented in June 1988, NAJ was positioned to serve as a major facility to preserve and provide important official documents as historical data under jurisdiction of Japanese government. Furthermore, under the Archives Law implemented in October 2000, placement of "historically valuable official documents" held by Diet and courts under the authority of NAJ was authorized with an agreement reached between Prime Minister and organizations in charge of documentation as occasion demands. NAJ plays an important role in passing down official documents - historically valuable common asset - to future generations.
Materials from the period between 1882 and 1885 (Sections 6 to 9), which are compilations that follow "Dajo Ruiten" (Sections 1 to 5), include records and clean copies of formal regulations. Those from the period after 1886 (Sections 10 to 79), which are compilations of the original records, consist mainly of records of laws and regulations.