Katsuhisa was the youngest son of Amako Masahisa and a grandson of Amako Kunihisa. His father, grandfather, and two elder brothers were executed on the orders of Amako Haruhisa in 1554. Katsuhisa, then a baby, was spirited away and at length became a monk living in Kyoto. When the Amako fell to the Môri in 1566, Yamanaka Shikanosuke approached Katsuhisa and convinced him to lead an effort to restore their clan. Katsuhisa fought for some time alongside Yamanaka in the Izumo-Bitchû area but was unable to make any lasting gains against the Môri. Defeated in Izumo at Nunobeyama in 1570, Katsuhisa and his supporters attempted a further penetration of the province in 1573. This endeavor also ended without success. Katsuhisa next allied with Oda Nobunaga, who by 1577 was at war with the Môri and pressing westward. Supported by Oda forces, Katsuhisa's men took Kozuki castle in Harima (1578), which they intended to use as a base for further attacks on the Môri. Soon afterwards, however, a large Môri army arrived and surrounded Kokuzi. When Katsuhisa learned that Nobunaga was unable (or unwilling) to send a relief force, he committed suicide in exchange for the lives of his men. The Amako thereafter disappeared from the political map.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005