This paper compares two significant trends in minority nationalism in a diasporic Okinawan community in Japan, namely, voluntary assimilation and assertion of cultural difference, from the formation of the Okinawan diaspora in Osaka in the beginning of the twentieth century to the early twenty-first century. Especially, it examines the ways in which the participants of Okinawan cultural activism from the 1970s challenged the official narrative of ‘Okinawans in Osaka’ as well as the homeland-based Okinawan nationalism. They did so by revealing the internal difference and hierarchy among Okinawans across generation and class, and by re-remembering historical incidents in a different context. Moreover, they later critically reflect on their own activism and its limitations and their unexpected contribution to reinforcing the ethnic status quo in a time of multiculturalism by promoting Okinawan ethnic culture to Japanese. In doing so, these activists illuminate issues in minority nationalism, such as collusion with the mainstream society, reinforcement of ethnic and social hierarchy in a larger context, reproduction of internal discrimination ­ that can go unnoticed when the Japanese-Okinawan relationship is only viewed in the framework of nationalism and ethnicity.