was an officer under the Uesugi clan.

Kagetsuna served as a very close confidante to Uesugi Kenshin

Uesugi Kenshin

was a daimyo who ruled Echigo province in the Sengoku period of Japan.He was one of the most powerful lords of the Sengoku period. While chiefly remembered for his prowess on the battlefield, Kenshin is also regarded as an extremely skillful administrator who fostered the growth of local industries...

. In both domestic and external affairs, Kagetsuna left his mark on Kenshin's regime. Kagetsuna was entrusted with distribution and defense of the supplies and reinforcements to the battlefield, during the expedition to the Kantō region

Kanto region

The is a geographical area of Honshu, the largest island of Japan. The region includes the Greater Tokyo Area and encompasses seven prefectures: Gunma, Tochigi, Ibaraki, Saitama, Tokyo, Chiba, and Kanagawa. Within its boundaries, slightly more than 40 percent of the land area is the Kantō Plain....

.
He fought alongside the Uesugi clan

Uesugi clan

The was a Japanese samurai clan, descended from the Fujiwara clan and particularly notable for their power in the Muromachi and Sengoku periods ....

 during the Battle of Kawanakajima.