Yoshimune became the head of his family in 1501. He was a rival of the Nagao of Etchû and fought a number of battles with them, including Shinjô in 1520. In that instance, Yoshimune was defeated by Nagao Tamekage after setting out to attack the latter's Shinjô castle. With his army broken, Yoshimune committed suicide at Fukagamiyama. After his death, the leadership of the weakened Jinbo clan appears to have passed to his younger brother Jinbo Yoshiaki, and then to Nagamoto, Yoshimune's son.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005