Ryōjun live in Iga with his father, mother, younger brother and family-owned ninja dogs. He is at the beginning of the story with hunting dogs and see the astonishment Kōga Clan's ninja dog, Sadamitsu.
The next night Ryōjun starts with the dogs to investigate the Koga border. They are forced to Kōga people attacked and one of the most successful damage the left hand of Ryōjun. Ōzaru and Kuma leave to bring him to safety. Ryōjun falls to the waterfall, when dogs jump after him. All survive, but they lose their weapons. One of the Kōga ninja dog almost to disclose their hiding behind the waterfall, but Ōzaru kills him.
The trio gets back into the woods and find a ninja dogs lying on the ground Kihē by the stomach to bleed. Ryōjun wonders why the father was in the woods and they talk to each other. He takes his father's hand and his father asks Ryōjun to take care of Taichi and their mother. Ryōjun to prove his father's death. After this Ōzaru administer it finds the hat and Ryōjun identify the Kai Shimoyama's.
Ryōjun carry home his father's body and then leaves to meet with Ōzaru, Tanba Momochi and other Iga ninjas, intends to tell his father's death and the traitor. Ryōjun overshadowed by Kaita, but later forced into battle against Kōga ninja dogs. He is wounded, but Ōzaru save him. Kōga Ninjas incendiary Iga one of the buildings on fire and Ryōjun shocked, because his family thinks he was inside. Ryōjun's family is, however, fit and Iga Ninjas win the battle.