信濃川
The Shinano River system has a long history of hydroelectric power generation, with the first hydroelectric power plant in Japan being located in the system. During the construction of a plant on the Shinano River in the Niigata Prefecture in July 1922, it was reported at the time that Korean workers were being mistreated and murdered. The Shinano River incident involved 1,200 workers, approximately 600 of whom were Korean, who were subjected to regular mistreatment by their Japanese foremen. The mistreatment included malnutrition, forced labour up to sixteen hours a day and severe beatings for those who tried to escape. News articles at the time alleged that up to 100 Koreans were killed during construction and that local farmers had reported seeing bodies floating down river. This incident occurred following the annexation of Korea by Japan and was partially responsible for the development of trade unions for Korean workers in Japan.