Being originally a samurai belonging to the Watanabe party in Settsu Province, which was under the umbrella of Settsu-Genji (Minamoto clan), he served Imperial Princess Muneko (Josaimonin), a daughter of Emperor Toba, as a Hokumen samurai (samurai on guard at the ex-emperor's palace).
元は摂津源氏傘下の摂津国渡辺党の武士であり、鳥羽天皇の皇女統子内親王（上西門院）に仕えていた北面の武士だった。