- Title: Etchû no kami
- Distinction: Etchû warlord
Nagamoto is thought to have been the son of Jinbo Yoshimune and ruled from Toyama castle. He was often at war with the Shiina clan and attacked the latter's Matsukura castle in 1559. Shiina Yasutane called on the assistance of Uesugi Kenshin of Echigo province, who captured Toyama on 1560/3/3. Nagamoto fled to Masuyama castle and continued to resist the Shiina from his remaining holdings. In 1562 Nagamoto again attacked the Shiina, and once again Uesugi Kenshin led an army into Etchû and defeated Nagamoto in the 10th month of that year. When Takeda Shingen became involved in Etchû's fortunes after 1566, Uesugi Kenshin sided with Nagamoto for a time - though internal strife within the Jinbo clan at length brought about the demise of the family as daimyô. The Jinbo were afterwards Uesugi vassals.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005