Sasaki clan are descended directly from Emperor Uda (868-897) by his grandson Minamoto no Masazane (920-993) (Uda Genji), Takaoka Muneyasu (1255–1326), grandson of Sasaki Yoshikiyo, is the first who took the name of Takaoka from his domain in Takaoka-mura, Enya-no-sato, Kamdo-gun, Izumo province.
It is a clan who prospered in future generations, in Izumo, Bingo, and Tajima.
After that, this clan moved to Tajima because they had become old Lord Koide Shigeoki's relative of Lord of Tajima (Koide Fusateru)'s vassal.
Sadamochi's 8th grandson Takaoka Sadami became Ashikaga Takauji's subordinate and there were distinguished military services.
And, because he had received the territory(Itanami-sho, Yosa-gun, Tango Province), the clan moved there.