Yukimatsu Masamori served as a bushō during the Sengoku period. He was the lord of Odaka Castle in Hōki Province.
The Yukimatsu clan were kokujin, or provincial landowners, based in Odaka Castle in the western portion of Hōki. From 1492, the Yukimatsu clan served Yamana Hisayuki, the governor of Hōki.
During the Eishō era (1504 to 1521), the Amago encroached on Hōki while Amago Tsunehisa backed Yamana Sumiyuki (a cousin of Hisayuki). After Sumiyuki prevailed in conflict against Hisayuki and became the governor, the Yukimatsu were ousted, but around the summer of 1562, recovered the castle with the backing of the Mōri clan.
In the year after returning to Odaka Castle, Masamori died of illness toward the end of 1563. Owing to Masamori’s death, the Yukimatsu clan rapidly declined.
After Masamori’s demise, his widow (a niece of Mōri Motonari) remarried a retainer of the Mōri named Sugihara Morishige. Together, they raised Masamori’s children including Kyūrō-Jirō. Sugihara used this along with Yabase Castle to keep in check the Nanjō clan based at Ueshi Castle.