仙台藩
Muneyoshi was the third son of Date Tadamune, the 2nd "daimyō" of Sendai Domain. His mother, Fusa, was a concubine and the daughter of Mitamura Matauemon. His childhood name was . From 1639, under his father's orders, he was raised by Suzuki Motonobu, a vassal of Sendai Domain, in Ōsaki, Shida District, as heir to the Suzuki clan. In 1649, at the time of his "genpuku" ceremony, he changed his name to .