In about 1233, he began serving the Kamakura bakufu (Japanese feudal government headed by a shogun), he distinguished himself, attended official events of the shogun as many as two dozen times ("Azuma Kagami" [The Mirror of the East]), was assigned as a kebiishi (official with judicial and police powers) in 1240, went up to Kyoto and served as an attendant in Daijoe (banquet on the occasion of the first ceremonial offering of rice by the newly-enthroned emperor) for the enthronement of Emperor Gosaga in 1242.
天福(日本)元年（1233年）頃、鎌倉幕府に出仕し始めると頭角を現し、将軍の公式行事に二十数回も出ており（吾妻鏡）、仁治元年（1240年）には検非違使に任命され、仁治3年（1242年）の後嵯峨天皇即位の大嘗会には、供奉役人として上京奉仕している。