He changed his family name to Gamo in 1788 (when he was 17) according to a story handed down in his family that his ancestor was the lord of the Aizu clan, Uzisato GAMO (when the son of Ujisato, Tatewaki Masayuki GAMO, relocated from Utsunomiya to Aizu, he left the pregnant daughter of Hukuda family in Utsunomiya and his father, Masae, was the fourth-generation descendant).
姓は、天明8年（17歳）に祖先が会津藩主蒲生氏郷であるという家伝（氏郷の子・蒲生帯刀正行が宇都宮から会津に転封の際、福田家の娘を身重の為宇都宮に残していった。それから4代目が父の正栄）に倣い改めた。