- Death: 1582
- Other name: Fujimaru Shinsuke
- Distinction: Ikkô general
Katsutoshi was originally a follower of the Ikkô-ikki of Kaga province. He was attacked in Daishôjiomote in 1555 by Asakura Soteki and fled, later taking up with the Uesugi clan of Echigo province. Uesugi Kagekatsu made him one of the defenders of Uozu castle in Etchû and when that place fell to a fierce assault by the Oda, Katsutoshi committed suicide.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005