In this Japanese name, the family name is Tokugawa.
Tokugawa Narimasa (徳川 斉匡 , June 3, 1779 – July 8, 1848) was a Japanese samurai of the Edo period. The son of Tokugawa Harusada, he succeeded Tokugawa Haruaki as head of the Tayasu branch of the Tokugawa house, which had been without a ruler for some time.
The original article can be found at Tokugawa Narimasa and the edit history here.