To survive after the rise of Hideyoshi HASHIBA (Hideyoshi TOYOTOMI) following Nobunaga's death, Kagekatsu had Yoshizane HATAKEYAMA (he had assumed the name of Yoshizane UESUGI at that time), Kagetora's adopted son and nephew, taken by Hideyoshi as a hostage in June 1586, and rendered homage and service to Hideyoshi.
信長の死後に台頭した羽柴秀吉（豊臣秀吉）に天正14年（1586年）6月、秀吉に養子であった甥の畠山義真（当時は上杉義真）を人質として差し出し、臣従して命脈を保った。