 Masayuki received great political clout with his rise in income, appointment as one of the shōgun's advisors, and regent during the minority of his nephew, the 4th shōgun Tokugawa Ietsuna.However, when offered the use of the Tokugawa crest, and the Matsudaira surname, he declined, out of respect to the Hoshina family and its retainers.The crest and surname were adopted during the lordship of his son Masakata.