- Died: 1583
Tsuneyasu was at first subordinate to Ogasawara Nagatoki of Shinano but joined Takeda Shingen and assisted him in his campaigns in that province. After the downfall of the Takeda in 1582, Tsuneyasu became a retainer of Ogasawara Nagayoshi. The following year he plotted to overthrow his lord but was discovered and made to commit suicide.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005