Nobuaki was served the Takeda family and was a retainer of Takeda Nobushige. At the Fourth Battle of Kawanakajima, he fought with great courage. In the course of the battle, Nobushige's head was taken. Nobuaki killed the man who had slain Nobushige and recovered his master's head. Takeda Shingen ordered that his younger brother's body (and head) be buried at Kawanakajima and the gravesite stands to this day. Nobuaki's son Masayoshi would eventually serve the Tokugawa family after 1582.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005