A young Tokyo theology student, Shirō (Shigeru Amachi), is set to marry his girlfriend, Yukiko (Utako Mitsuya), the daughter of his professor, Mr. Yajima. After announcing the engagement, Shirō's dark and unsettling colleague, Tamura (Yōichi Numata), drives Shirō home, suggesting that Shirō had been sleeping with Yukiko for some time. Taking a side street at Shirō's request, Tamura hits and kills drunken yakuza gang leader, Kyōichi. Though Shirō wants to stop, Tamura keeps driving, stating that it does not concern him and that ultimately, the murder is Shirō's fault for asking him to drive down the street. Unbeknown to either of them, Kyōichi's mother (Kiyoko Tsuji) witnessed everything and resolves to find and kill them.