All his life, Seikei has wished to be a samurai. But in 18th-century Japan, everyone was destined to remain at the level of one's birth--and Seikei's father was a merchant, the lowest class. While traveling on the Tokaido Road, Seikei and his father stop at an inn. There, Seikei meets a girl who tells him a ghost story that is so spooky that he cannot sleep. In the middle of the night, the door to his room opens and he sees a ghost holding a shiny red stone. In the morning, a powerful daimyo lord complains that a precious ruby has been stolen from him--and he accuses the girl Seikei had met. Soon, a judge named Ooka arrives. In the Japan of that time, judges were called on to solve crimes and obtain confessions. Seikei, to save the girl, tells what he has seen. Judge Ooka takes him along and they soon discover that the thief was not a ghost, but an actor in a traveling theater troupe. Judge Ooka sends Seikei to "follow the path" that will lead him to the criminal. He eventually joins the troupe himself, and is astonished to see the thief leave the jewel at the shrine of the goddess Amaterasu. Puzzled, Seikei continues on with the actors to the Shogun's capital of Edo, where they are scheduled to give a performance for the same daimyo whose ruby was stolen. In the story's thrilling climax, Seikei discovers what a true samurai will do to preserve his honor--and he himself attains his greatest desire.