An act prejudicial to the occupation forces: Migration controls and Korean residents in post-surrender Japan

This article uses previously neglected archival material to shed new light on issues of frontiers, migration and the status of Koreans in occupation-period Japan. When Japan surrendered on 15 August 1945, there were some two million Koreans in Japan. The occupation authorities had little understanding of the Korean community in Japan, and the policies they introduced towards them were often harsh and contradictory. In particular, the imposition of stringent migration controls to prevent Koreans from moving back and forth across the border between Korea and Japan had severe consequences for Japan's largest ethnic minority. Occupation-period border controls were largely enforced by members of the British Commonwealth Occupation Force (BCOF), including British, Australian, New Zealand and Australian troops. Using BCOF archives, the article shows how the occupation forces cooperated with the Japanese police, sometimes in the process reviving wartime social control measures, in order to control the mobility of Korean in Japan. This collaboration had a lasting impact on the status of the resident Korean community and of other foreign communities in Japan. BCOF also appears to have provided the initiative for the introduction of Japan's controversial post-war alien registration system.1.