Unlike many Ayakashi, who were transformed humans who fell into their corrupted, monster-like state, Dokoku was born of the Sanzu River, who is the embodiment of pure anger and rage. However, events changed the day he started to hear a sorrowful shamisen, through a crack between the human world and the Sanzu River, making his anger abate and calming him down, quite possibly for the first time. The shamisen played through the crack for three years, before the player Usuyuki committed the act that made her fall into becoming Dayu and transforming her beloved Shinza into her shamisen. Dokoku met her as she arrived on the Sanzu River and chose to protect her from then on, seeing the importance of her shamisen as a means to prevent him from completely raging in both worlds. Act 40: The Honorabl