This paper looks at public discussion surrounding the enactment of Japan's Prostitution Prevention Law in 1956. It picks up the opinion of commentators that the Japanese sex industry continued to flourish even after 1956 because the geisha system was left out of the law. (1) The paper asks why the geisha system was left out of Japan's Prostitution Prevention Law, and why this exclusion was a boon for the country's sex industry. It then broaches a theoretical explanation for the role the geisha system played in the success of Japan's postwar sex industry. This explanation draws on feminist Catharine MacKinnon's idea of the 'Playboy standard'. (2) The 'Playboy standard' is a phrase that stands for ...