Oga Yashiro is a traitor who offered to let Takeda Katsuyori into the Tokugawa-controlled castle at Okazaki. His plot was discovered and he died by the bamboo saw after 7 days.[1]
Notes and References
Book: Turnbull. Stephen. Battles of the Samurai. 1987. Arms and Armour Press. London. 9780853688266. 81.
