The year is 1457. Princess Fuse, daughter of Yoshizane Satomi, Lord of Awa province, is forced into matrimony with her dog, Yatsufusa. This situation occurs when, under siege by the neighboring army of Lord Kagetsura Anzai and facing starvation. Yoshizane makes a desperate, last-ditch promise to the animal. Ultimately, the princess is killed, along with Yatsufusa, by a bullet from the gun of Daisuke Kanamari, who had come to rescue her. At the moment of Fuse's death, eight spirit beads from the necklace she was wearing disperse into the sky and the legend of the dog warriors begins.

In the midst of the disturbance in Otsuka village caused by Hamaji's disappearance, there comes the arrival of evil itself, personified by the jindai and his retainer, to whom the village chief and his wife soon fall prey. Only one man, Sosuke, is able to stand up to them, though it is he who is ultimately arrested and blamed for the murders of his step-parents. Meanwhile. Shino arrives in Koga and is granted an audience with the Shogun, Nariuji Ashikaga. The legendary Murasame sword that he offers up, however, is revealed to be a fake, and Shino becomes a hunted criminal. But the man released from captivity in the castle dungeon and assigned to capture Shino turns out to be none other than the fourth dog warrior, Genpachi Inukai.