Kōzuki had been taken by Toyotomi Hideyoshi the previous year and entrusted to Amago Katsuhisa.

Amago's loyal and heroic general Yamanaka Yukimori was captured and executed.

[1] Oda Nobunaga was running out of qualified battle-hardened lords to hold his territories, so Amago Katsuhisa though a member of the Amago clan samurai class, who was not especially experienced or trained as a warrior, he was called to become lord of Kōzuki castle from Kyoto, where he was studying to be a Buddhist monk.

The Amago forces under Yamanaka Yukimori were so vastly outnumbered and surrounded in the castle that victory was impossible.

The offer was accepted, Amago forces surrendered, and Katsuhisa committed suicide.