 Tomiko is a conductor in a rural bus driven by the handsome Niitaka. Tomiko had received a letter from her best friend Tsuyako, a conductor in another bus company, just after Tsuyako was killed in a bus accident. Tsuyako wrote that she felt that her fiance and driver, Niitaka, planned to kill her. Tomiko therefore plans to take revenge on Niitaka. However Tomiko falls in love with Niitaka, even though she also suspects him of being the Tokyo bus driver serial killer, who killed his female conductors after tiring of them.