A withered
biwa player narrates a tale of how 900 years ago, the
Genji clan sought the
Imperial Regalia to unite the
emperor's throne. They defeat the rival
Heike clan at the
Battle of Dan-no-ura, wherein the
child emperor drowns while carrying the
Kusanagi-no-Tsurugi, the legendary Japanese sword.
Three hundred years later, agents of
Ashikaga Yoshimitsu hire young Tomona and his father to retrieve a box from a Heike shipwreck. They find a sword inside the box. Not realizing that it is Kusanagi-no-Tsurugi, Tomona's father unsheathes the sword, letting loose a blade of energy that cuts him in half and
blinds Tomona. Tomona then goes on a years long journey to find answers for what happened, with the ghost of his father accompanying him. He meets a member of a whole troupe of blind biwa players, and decides to learn the biwa and join the troupe. Tomona changes his name to "Tomoichi", but the name change makes it difficult for his father's spirit to find him. At the same time, a
Noh dance troupe leader dons a demonic mask. A series of murders of biwa players follow, and then the leader's third son is born with three stubby limbs, a very elongated right arm, skin covered in scales, and a hideously deformed face. The troupe leader has such contempt for his deformed son that he forces him to always wear a mask and treats him like a dog. But one day, the deformed son sees his father try to teach Noh dancing to his other sons. The deformed son practices along with them, and his dance magically restores his legs. The deformed son wanders the village and soon meets Tomoichi. He bonds with Tomoichi as he can't see his deformity, and so he reveals to him that he has chosen the name "Inu-Oh" (lit. "Dog King") for himself. Tomoichi tells Inu-Oh about how he can see his father's spirit, and he then notices that many spirits of Heike warriors surround Inu-Oh, telling him their stories. This vision inspires the two to form a new performing troupe, with Tomoichi now renaming himself "Tomoari". Soon after, a long-haired Tomoari debuts the new act on a bridge, performing his song in a style resembling modern
hair metal. Below the bridge, Inu-Oh dances to the music, telling a story of how the Heike soldiers clung on to their ship in retreat but had all their arms cut off. At the end of the song, both of Inu-Oh's arms change to normal length. Their act is an instant hit, and Tomoari and Inu-Oh become huge celebrities. In their next performance, about the Heike warriors waiting for a "whale that never arrived", the scales on Inu-Oh's skin disappear. But the new troupe arouses the attention of Ashikaga, who only wants his clan's version of the Heike stories told. He sends agents to Inu-Oh's now envious father, offering fame if he sabotages his son's act. The troupe's next act reveals the truth behind Inu-Oh's origin: his father made a deal with the demon mask for fame. The demon mask demanded the lives of biwa players, and the innocence of his unborn son. The murders that followed released the spirits of Heike soldiers that followed the players, but the spirits flocked to Inu-Oh instead of his father, helping him win fame and undoing his curse. His father demands the mask kill Inu-Oh, violating the terms of their original agreement. Outraged, the mask kills Inu-Oh's father instead. At the end of the performance, Inu-Oh's face is restored. However, Ashikaga cracks down on the troupe, forcing Tomoari to stop playing. Ashikaga himself demands that Inu-Oh perform only the official version of Heike history, or else he will behead Tomoari. Inu-Oh concedes, but Tomoari continues to perform and speak out against the Ashikaga clan, so the clan's men behead him. Inu-Oh goes on to more years of fame as a Noh dancer, but he is forgotten after his death. The narrator turns out to be Tomoari's spirit, who has remained on Earth up to modern times, and now uses his original name "Tomona". Inu-Oh's spirit appears, explaining that it took 600 years to find Tomona since he changed his name. Inu-Oh restores Tomona to his youthful form, and reverts to his deformed version. The two then perform again. ==Characters==