Are parliamentarians involved in normative power diffusion? This case study of Japanese parliamentarians’ international activities shows how they engage in international norm diffusion at interparliamentary meetings in a way that multiplies the normative power efforts of Japan’s government. While parliamentarians are neither official foreign policy actors nor diplomats, they actively promote topics that support Japan’s normative power interests and employ mechanisms identified for normative power diffusion. Thus, parliamentarians become multipliers of Japan’s normative power efforts and have the ability to reach legislators in Japan’s key partner countries. This paper argues that, when abroad, Japanese legislators adopt the identity of an international representative of Japan, who supports promoting Japan’s interests in various areas, such as climate change, overseas agricultural investments, or regional financial stability.