Seki Kazumasa
 Seki Kazumasa (関 一政 1564 – November 19 1625) was a Japanese daimyo of the late Sengoku period through early Edo period who was a retainer of the Oda and Toyotomi clans. His court title was Nagato no kami (長門守). Kazumasa took part in many of the major campaigns of the Toyotomi clan serving as a yoriki under his brother-in-law Gamō Ujisato. In the early Edo Period he served under the Tokugawa clan at the Sieges of Osaka.