The corpse of a debt collector, Sakai, is found in the Dobu River in Tokyo. Kinoshita, a shoe shiner who was in debt to Sakai, was soon apprehended. During interrogation, Kinoshita said that he was the one who killed Sakai. However, after a while, he admitted that he lied, because he thought that in prison he could eat plenty of rice for free. The investigation established that Sakai was a repatriate from Manchuria, and after returning to Japan, he had a wife, Rie Kawai. The investigation begins...