Black Snow tells the tale of a disturbed young man who, after spying on his mother with a black serviceman, finds himself unable to attain sexual arousal unless fondling a loaded gun. Later that night, he murders the GI before running amok through the building and finally slaying his mother's sister...
Miyoko Sekiguchi, who works at a second-rate trading company, and car mechanic Koji Fukumoto are in love. The morning after Koji and Miyoko went out for a drive, the strangled corpse of a call girl is discovered in Toyamagahara. Chief Akagi, Detective Sergeant Sawada, and the other detectives begin to suspect Koji during their investigation. Koji insists he's innocent, but has no evidence to prove it. Even when detectives come to Miyoko's home and workplace and her coworkers begin to look down on her, Miyoko continues to trust and love Koji...