Postwar Tokyo. Pin (Jukichi Uno) and Toku (Taiji Tonoyama) live in the squatter area of Kappanuma, also known as "The Ditch". Pin and Toku are avid gamblers. They take in Tsuru (Nobuko Otowa), a slightly demented woman who has run away from a geisha house. In order to rip Tsuru off, Pin lies that he's a student who can't afford his school fees. Tsuru willingly whores herself to support Pin. Eventually the neighbours start to exploit Tsuru as well.