Hisanao married a daughter of the Chikugo Tachibana clan, the descendants of TACHIBANA no Kimiyori (the ruler of the region), and adopted as a son of the clan, and with support of his influential power, founded the Kamachi clan by placing his base in the Kamachi Castle.
同地を支配していた橘公頼の子孫の筑後橘氏の娘婿となり、その勢力を背景に蒲池城を本拠地として蒲池氏の初代となる。