Yasusada's younger brother Shigesada SAJI was so young when he took over Saji-go that Yasusada worked as Goshi shiki of the Saji-go instead of his younger brother for a long time.
佐治郷を継承した弟の佐治重貞は当時幼少であったため、康貞が長らく佐治郷司職の代行をしていた。