Hisatsuna served Amako Yoshihisa and joined Yamanaka Shikanosuke in attempting to relieve Shiraga castle, surrounded in 1563 by the Môri. While Shiraga fell, Hisatsuna distinguished himself in battle. When Gassan-Toda castle was isolated, Hisatsuna again proved himself a worthy retainer, opposing surrender as long as possible. When Yoshihisa finally decided to give in, Hisatsuna was sent as an envoy to the Môri to arrange the surrender. His conduct and past bravery so impressed the Môri that they offered him a position as a retainer, which he respectfully declined. Instead, he ended up going to Kyoto, where he helped convince Amako Katsuhisa to give up the priesthood and lead an army to restore the Amako family. He is thought to have been as important as the better-known Yamanaka Shikanosuke in the army that landed in Izumo in 1569 and clashed with the Môri forces there throughout the following year. He later met with Oda Nobunaga to secure the assistance of that powerful warlord, who by 1576 was also at war with the Môri and in the course of the session impressed Nobunaga with his bearing. When the Amako army was surrounded in Kozuki castle by the Môri in 1578, Hisatsuna stayed with Katsuhisa until the last moment. When Katsuhisa committed suicide, Hisatsuna shaved his head and became a monk, spending the remainder of his years in Awa province. His elder brother Yukitaka had earlier accompanied Yoshihisa into confinement in Aki province and thus did not take part in the effort to restore the Amako.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005