The Kutsuki were a branch of the Sasaki family hailing from Omi Province. They served as the stewards of the Kutsuki manor in that province in the Kamakura period, and the house continued through the Warring States period and into the Edo period, when some of their members became bannermen (direct vassals of the shogun) or daimyo (provincial lords). "The archives of Kutsuki family" consist of historical documents passed down in the family through the years. The Cabinet Records Bureau purchased them from the Kutsuki in 1888. Containing more than 1,060 documents, the archives were designated an important cultural property in the first year of Heisei( 1989).
This "kudashi bumi" (a letter sent from a superior to subordinates, conveying decisions) was sent under the name of Hojo Yoshitoki (1163 - 1224), in his capacity as regent in the Kamakura shogunate. Dated 25 August the 3rd year of Shokyu (1221), it is the oldest document in the archives of the Kutsuki family. The "Mutsu-no-Kami" ("Ruler of Mutsu Province") noted in the signature refers to Yoshitoki. The text is an appointment of Taira Yasunari to a position of proxy control over the Aritadosan manor in Harima Province.