Shibata Katsuie
After Toyotomi Hideyoshi's victory over Shibata Katsuie in 1583, Ieyasu expressed his congratulations to Hideyoshi through Kazumasa. Later, Kazumasa and Sakakibara Yasumasa accordingly issued statements attacking Hideyoshi, due to the Tokugawa's decision. Kazumasa served at the Komaki headquarters during the Komaki-Nagakute Campaign.