Based on the historical materials, the following facts were confirmed; the Kaminokuni family usually used the name of Minato family, and at latest in the Tenmon era, the family was raised to Kyoto fuchishu (warriors from Kanto or Tohoku region in the Muromachi Period, who served Seii taishogun in Kyoto under a direct master-servant relationship), and that, the family had a certain connection with the central government as associating with Hongan-ji Temple and the Hosokawa clan, and the family proclaimed itself 'Saemon no suke' (assistant captain of the Left Division of Outer Palace Guards) for generations.
上国家は、一般的に湊家と称し、遅くとも天文(元号)年間には京都扶持衆となっていること、代々「左衛門佐」を名乗り本願寺や細川氏とも誼を通じるなど中央との交流があったこと等が史料から確認されていること。