One of the officials who settled in Usu-gun with Kuninari Date and was in charge of accounting and finance was a retainer named Sukesaburo Osasuke Sato, who moved to the area with his family at the age of 66 for pioneering work.
Each of his poems is not only about the name of a place, but also about the scenery of the pioneer days and the feelings of the people of the time, and has become a rare literary heritage of pioneering literature.
　In 1982, the Date Local History Study Group began a project to leave a monument to the land where Osanori Sato wrote his poems, and in 1989, the twenty-eight poems were completed and erected on the monument.
　Kuninari, the feudal lord of the Date family, and other vassals also left behind many poems, which shows that the Date family was a cultured family with a history of poetry.