Tsuchiya Sadatsuna
Sadatsuna originally served the Imagawa and was known as Okabe Chûbei. He joined Takeda Shingen and adopted the name by which he is better known. He was something of a naval commander and had 12 vessels under his control, though he would be killed fighting on the ground at Nagashino in 1575.
References
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005