Mitsukuni Tokugawa (1628-1700), in obedience to an Imperial command by Emperor, compiled the records in the Shoko Bekkan (彰考別館) annex building, which was specially built within the premises of the Mito castle in the 3rd year of Teikyo (1686). The records were presented to the Imperial Court and the Shogunate in the 7th year of Hoei (1700). The collection is a compiled and classified edition of the complete traditional and regular customs at the Imperial Court inherited from the Heian period and other irregularly held ceremonies and events. The collection provides historical materials of great help for the study of ancient practices and usage as well as an institutional history.