Since the 1990s sushi has become a global product with a transnational market. Hybridised and localised sushi like California Rolls and Spider Rolls are now even being reverse-imported to Japan as ‘genuine American sushi’. This article examines some attempts to re-nationalise global sushi, both from the Japanese state and from the vernacular media. We argue that, while popular reporting on the ‘overseas sushi boom’ generates a sense of national pride over ‘them’ eating ‘our’ food, the state's position is a more strategic one. It operates with a clear motive of increasing sales of Japanese food products overseas, mobilising the image of authenticity for this specific purpose. Both state and popular expressions of culinary nationalism claim Japanese ownership of culture not only in its ‘authentic’ forms but in its multiple, creative, hybrid and fusion forms. By examining Japanese responses to foreigners consuming sushi, we hope to provide some insights into the relationship between food, national culture, authenticity and globalisation. A further objective is to understand Japan's culinary nationalism within the larger context of the ‘soft power’ and ‘cultural diplomacy’ discourse.