Rikiou was one of Takeda Gohei's hunting dogs. Gohei wanted a strong dog to fight bears so, he got a Tosa. Rikiou was fed bear meat and was an exellent dog. But Rikiou did not know what it was like to fear an enemy and so, during his first hunt, when a bear shown up, Rikiou attacked without hesitation, ending up killed, as the bear crushed his head under his paws.