Ocho was a monster that slew and ate the villagers of an anonymous town. For a month, she prevented any from leaving the town. Every night, Ocho would prowl the village and slay another villager, leaving their remains to be discovered in the morning. The villagers attempted to fight back, but of the two dozen men sent to hunt her, only one, Gon, returned alive, though without his sanity.
Shortly thereafter, the wandering ronin Miyamoto Usagi entered the village. He encountered Ocho in her monstrous form on the outskirts of the town and wounded her right paw, driving her off. Ocho (in her human form) invited Usagi to stay at her house, and claimed that her wounded hand was the result of an accident sustained while sharpening chopsticks. However, Usagi caught sight of Ocho's true self in a reflection, and realised that Ocho herself was the monster terrorising the town. Usagi confronted Ocho again, and would have been slain save for the intervention of Gon, who impaled Ocho upon a spear before being slain. Usagi was then able to kill Ocho and end her reign of terror forever.