In the late 2000s, a new wave of xenophobic activism known as the ‘Action Conservative Movement’ (ACM) began to engage in prominent actions against ethnic minorities. Its aggressive use of hate speech confirmed fears of a rightward shift in Japan, echoing the rise of nationalist movements elsewhere around the globe. However, as the ACM moved from online organizing to high-profile public protest, pre-existing factions of rightist activists challenged ACM methods and viewpoints on multiculturalism. These ‘fights on the right’ highlight the diversity of rightist groups that are often treated monolithically in academia and the media. The critique some rightists made of the ACM’s xenophobic activism was based on a view of ethnicity that embraced Japan as a multi-ethnic empire—an iconoclastic view itself, and a reflection of Cold War geopolitics, the dynamics of domestic political polarities, and Japan’s colonial legacy manifested by ethnic minorities. It built as well from the cultivation of a particular form of anti-establishment ethos. Based upon my ethnographic fieldwork since 2005, this article offers a detailed typography of several generations of right-wing activism in Japan and an examination of how their diverse views of social citizenship, activist method, and ideological commitment have come into conflict as they grapple with ethnicity in contemporary Japan.