The Kaminokuni family ruled Ogashima in Dewa Province (present Oga City, Akita Prefecture) and Tsuchizaki Port (present Akita City, Akita Prefecture), and later it came to control the whole Akita Country and called its residence Akita-jo Castle.
上国家は出羽小鹿島や土崎港（現秋田県秋田市）を領し、後に秋田郡を制して秋田城を称した。