Since the mid-1990s the Japanese government has pursued reconciliation initiatives aimed at fostering understanding between Japan and former POWs. Nevertheless, the POW issue remains relatively unknown in Japan. This article describes the profile and activities of the POW Research Network Japan (POW kenkyūkai), a civil society group consisting of professional and shimin (citizen/non-professional) researchers as well as concerned citizens investigating the subject of Allied POWs in Japan. The article explores how POWRNJ participated in and contributed to the contestation of memory of the Asia-Pacific War (1931–1945) during the last decade. It describes the manner in which the group promoted its views and strived to achieve its goals. On the basis of these findings, the article identifies the kind of roles the group played, and how it mattered in the debates on Japan's wartime past.