 His courtesy title was "Mimasaka-no-kami" and "Jijū", and his Court rank was Junior Fourth Rank, Lower Grade.Yukiaki was the eldest son of Tamura Kuniyuki and became "daimyō" in 1857 on the latter's death.However, in 1863 he was adopted by Date Yoshikuni to become heir to Sendai Domain and changed his name to Date Mochimura.