 His childhood name was Ogimaru (於義丸) given by his grandfather, "Shōgun" Tokugawa Yoshimune.In 1747, on the order of his uncle, "Shōgun" Tokugawa Ieshige, he became the adopted son and heir of Matsudaira Munenori of Fukui Domain.He became "daimyō" two years later on Muninori's death.