During the half century (1854–1904) which followed the opening of Japan's ports, Westerners scrutinized the rediscovered archipelago and attempted to classify its inhabitants within their racial system. Despite the claim for ‘scientific’ objectivism, Western racial views of the Japanese were largely dictated by contemporary political and moral attitudes toward Japan. Hence, writings on the Japanese ‘race’ reflected not only the racial knowledge of the period but also the asymmetry between the West and Japan. These writings embodied a genuine discourse: they were propounded in texts, historically located, and displayed a coherent system of meaning. Critically, the Western discourse regarding the identity of the Japanese people aimed to maintain, and even produce, power relations between the colonial powers and the local population, and as such it exerted ideological influence on both Western readers and the Japanese. The present article traces this racial discourse, and attempts to explain the rapid transformation of the image of the Japanese people from an almost unknown racial entity to a national group Westerners perceived as a major racial threat.