In 1200, when Kagetoki KAJIWARA was expelled, Hirotsuna, who was working as a saemon no jo (third-ranked officer of the Left Division of Outer Palace Guards), searched and captured the roju (vassals) who remained in Kagetoki's mansion, that faced the Gojobo-mon Gate in Kyoto, on March 13.
正治2年（1200年）、梶原景時が排斥されると、2月20日、左衛門尉を務める広綱は、京五条坊門面の景時邸に在る郎従を追捕する。