Kagenori became a Tokugawa retainer following the fall of the Takeda and was made a page to Tokugawa Hidetada. He is known to have seen service at the Osaka Winter Campaign (1614) and is reputed to have been sent to the Osaka garrison as a spy by the Tokugawa. Kagenori is attributed with writing at least part (if not most) of the Koyo Gunkan, the well-known history of the Takeda of Kai in the 16th Century, which in fact amounts to a piece of hagiography extolling Takeda Shingen. From this work comes the popular view of the events surrounding the Fourth Battle of Kawanakajima, a contest otherwise poorly documented in more reliable sources.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005