[Machine Translation] A middle-aged woman was stabbed to death in Kyoto, and her friend was killed in Tokyo using the same method. In both cases, the Chinese characters for "yin-yang" were left at the scene of the murders. Inspector Totsukawa notices a photograph displayed in the room where the murders took place. There, four men and women, including the victim, are laughing in Las Vegas. They were a group of crooks who gambled their way into other people's lives. As the investigation progresses, the investigators realize the connection between the four men and the yabusame (horseback archery) rituals in Kamakura. Eventually, a suspect emerges, but he has an ironclad alibi...