In accordance with the National Archives Law No.79 (1999), the core function of preserving "government documents and records of importance as historical materials includes all material relating to (1) decision-making on important items of national policies, and (2) processes of deliberation, discussion, or consultation prior to reaching any decision-making, and the process of enforcing policies based on decisions made. The transfer of what are deemed historically important materials from the various ministries and agencies is carried out on a regular basis in accordance with the Transfer Plan prepared and revised by the Prime Minister for each fiscal year. Preservation, restoration cataloging, microfilming and digitization are all important aspects of the archive's rsponsibilities. However, the National Archives is in the process of becoming something more than simply a historical repository, because it is also a complex of structures, processes, and epistemologies which are situated at a critical point of the intersection between scholarship, cultural practices, politics, and technologies.
In November 1959 the President of the Science Council of Japan issued a recommended establishing a National Archives to prevent scattering and loss of official documents and to facilitate public access. In July 1971, the newly-created Archives began receiving, assessing, and cataloging government documents and records of importance as historical materials; and also, the Archives focused on the conceptually distinct program designed to encourage wider interest by mounting exhibitions and fostering research.
In July 1998, the Tsukuba Annex (Tsukuba Gakuen Toshiwas) was established in Ibaraki Prefecture in order to expand and improve the storage of archival materials.
A Cabinet resolution in 1999 led to the creation of the , which opened in November 2001. The center digitalizes data from various national institutions, such as the National Archives, Diplomatic Record Office of the Ministry of Foreign Affairs, and the Military Archives of the National Institute for Defense Studies of the Japan Defense Agency, and provides the digital data through the Internet.
The enhanced independence of the achives was designed to help further its institutional focus on measures for the proper conservation of historical materials. By assigning the prerogatives of record keeper to the archivist, the institution's acquisition policies, finding aids, and various institutionalized predilections produce subtle consequences. These are factors which mediate between scholarship and information. The National Archive is not merely a repositories of data; rather, the institution has a long-term effect by the extent to which the archive preserves fragments of culture which endure as signifiers of who the Japanese are, and why they came to be the way they are.
From April 2005, the digital archive system in this website has provided high-resolution pictures of a range of holdings, including the materials designated as the Important Cultural Properties of Japan. The collections in the National Archives provide tangible evidence of memory for individuals, communities, and the state; and the archives are integral in a proces of defining memory institutionally within Japan's prevailing political systems and cultural norms.
The National Archives has evolved as a model for developing prefectural and municipal archival collections -- some of which predate the establishment of the national institution. In these smaller institutions, similar activities of preservation, restoration, cataloging, microfilming and digitization are evolving. For example, the Digital Gallery includes digitized photos of the stack room for official documents in Shiga Prefecture in 1924. These images were appended to a report submitted by the prefectural governor to the chief of the cabinet secretariat in November of that year. Shiga's governor was describing the progress of work intended to modernize standards and procedures for compiling and storing of written records, which was expected to produce improved efficiencies in administrative services.