- Died: 1564
- Title: Echizen no Kami
Masakage was Uesugi Kenshin's brother in law, though he had initially fought against him in support of Nagao Harukage. He later became Kenshin's retainer but may have been assassinated on Kenshin's orders. He was the father of Uesugi Kagekatsu.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005