On May 1st, unions all over Japan celebrate May Day, the international day for workers. Workers gather together at parks and hold demonstrations and parades. May Day has its origins in a strike that occurred in the United States on May 1, 1886, a strike that called for an eight-hour workday. Prokino recorded the May Day every year from 1927 to 1932. Among these films, this work is the only one that has survived. However, only its first part has survived. The original film depicts the march to the Ueno Park where the rally was dismissed. Iwasaki Akira coordinated the entire Tokyo Prokino organization as it photographed the 1931 May Day celebrations. They shot in both 16mm and 35mm (other 35mm productions were planned, but this is the only one that achieved completion). A 16mm print was circulated around the countryside by mobile projection units, and a 35mm print was shown at Soviet film nights in Tokyo and Osaka.