Tsuda Kazunaga served as a bushō during the Sengoku period.

His common name was Kenmotsu.  He was also called Suginobō Kazunaga.  His younger brother was Suginobō Myōzan.  His children included Tsuda Kazumasa, Suginobō Shōzan, and Tsuda Arinao.

He used the surname of the Tsuda family founded by Tsuda Masanobu in the Muromachi period, a branch of the Tachibana-Kusunoki clan.

Kazunaga served as the lord of Hanzaki Castle in Kii Province and as the head of warrior monks known as the Negoro Group from the Negoro Temple in Kii.  Skilled in the arquebus, he created the foundation for the art of rifles in Japan, known as the Tsuda-style art of gunnery.

Kazunaga traveled to Tanegashima, purchased one arquebus from the landowner, Tanegashima Tokitaka, and then had a craftsman, Shibatsuji Seiemon, manufacture replicas.  After bringing knowledge of arquebuses to the Kinai, manufacturers arose in Kii and Sakai leading to the mass production of units.

According to one account, Kazunaga was originally a resident on Tanegashima.

He died in 1567 at the age of sixty-nine.