Obu Toramasa, who according to some accounts was a descendant of Minamoto no Yoshiie, was a chief vassal of the Takeda Clan who first served Takeda Nobutora, then his son Takeda Shingen, and later became tutor to Shingen's eldest son Yoshinobu. He was one of Shingen's Twenty-Four Generals and was nicknamed "The Wild Tiger of Kai." However, he was implicated in a plot to rebel against Shingen by Yoshinobu and was forced to commit suicide at the age of 62.