Lord of Kozan Castle in Bitchu. He succeeded his father Hisatomo, who died from wounds suffered at the 1567 Battle of Meizenji. In 1571, while on campaign with Mori Motonari in Kyushu, Amago forces seized Kozan Castle, which he recaptured. In 1575, when his brother-in-law Mimura Motochika broke with the Mori, Hisanori joined him out of loyalty and fought at the Battle of Bitchu-Matsuyama, but was defeated, fled to nearby Okaya Castle, and was surrounded by Kobayakawa forces after a retainer's betrayal, taking his own life at age 19.

A spirited young lord who recaptured his own castle after it was seized. Valuing loyalty above safety, he chose to fight alongside his brother-in-law Mimura Motochika even against the odds.

His dramatic death at just 19 is remembered alongside the ruins of Kozan Castle as a symbol of the tragedy that befell the Mimura-allied local lords in the Bitchu Rebellion.