Thanks to the Ritsuryo system (a system of centralized government based on the ritsuryo code), Naiki (Secretary of the Ministry of Central Affairs), Geki (Secretary of the Grand Council of State) and Zushoryo (the Bureau of Drawings and Books) developed a method of collecting records and official documents, although it was not yet perfect; this development led to the collection of records rich in content.
また、律令制が整えられたことにより、内記や外記、図書寮などに不十分ながらも記録や公文書が蒐集される仕組が形成されてきた事が記録の充実をもたらすことになる。