In July 1607 he inherited the clan leadership role from his father Hideuji whereupon Hirotsuna became a vassal of the Edo shogunate (and a fief in Tanba Province of over 3,570 koku).
慶長12年（1607年）7月、父秀氏の家督を継いで、広綱は江戸幕府の旗本となった（知行は丹波内3,570石余）。