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 "The archives of Kutsuki family" consist of historical documents passed down in the family through the years.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).
Dated 5 July in the 2nd year of Genki (1571), this is a vermilion seal certificate that was sent by Oda Nobunaga (1534 - 1582) to Kutsuki Yagoro (Mototsuna). Shaped like a horse's hoof, the seal impression reads "Tenkafubu (may our forces cover the land)," and manifests Nobunaga's ambition to conquer the whole country by force. Mototsuna had sent a messenger to Nobunaga to pledge his allegiance. In the letter, Nobunaga gives his approval of Mototsuna's position as governor of Sudo manor in Oumi Province and grants him an additional domain.