The leader of the wild dogs in the Kiso Mountains is a huge red dog feared as a "demon dog." It was captured by dogfighters Genzo Sakurai and Haruhiko Sakurai. The dog was named Musashi to be kept as a fighting dog. However, when he bit off his opponent's tongue in his first fight, he was banished. Genzo, no longer able to earn money from its fights, turned Musashi into a bait dog. Musashi was muzzled and blindfolded to be attacked by other dogs, but Haruhiko was struck by the way Musashi tried his best to fight, and decided to return him to dogfighting. A comeback match against the fearsome Muramasa was arranged through the Nishiyama, an influential figure in the local dogfighting scene. Musashi narrowly won, but was forced to retire due to injuries sustained in the fight. After that, Musashi began to attack Masamune, a newly acquired fighting dog, every night. Haruhiko's father, annoyed by the dog's refusal to listen to his repeated warnings, finally killed Musashi with a gun! One year later, when they saw Masamune fight for the first time, they were surprised to see that his fighting style was similar to Musashi's. All that time, Musashi had been teaching his own techniques to train the younger dogs. Genzo regretted his actions and closed his dogfighting business, while Haruhiko wept and apologized at Musashi's grave. A tragedy between humans and animals who couldn't properly communicate, comes to a close...