Title: Musashi Shugodai

Ooishi Sadahisa was a warlord of Musashi, son of Ooishi Sadashige and master of Takiyama Castle. He succeeded his father as head of the family, but in 1546 upon the Uesugi Clan's defeat to Houjou Ujiyasu in the Battle of Kawagoe Castle, he married his daughter Hisa to Ujiyasu's third son Houjou Ujiteru and adopted him, upon which he retired and yielded both Takiyama Castle and his title to Ujiteru. After retirement he worked to further diplomatic relations between the Houjou and Uesugi Kenshin.