The number of Japanese-Brazilians working in Japan grew from less than 15,000 in 1989 to more than 300,000 in 2006. This rapid growth in migration was initiated by a law change in Japan allowing third-generation Japanese-Brazilians to work in Japan, the “push” of poor economic conditions in Brazil, and the “pull” of a booming economy in Japan. Cultural links between Japan and the Japanese-Brazilians, together with the development of highly efficient organized labour recruitment networks, have acted to foster this, leading to the creation of what some experts believe to be a self-sustaining migration system. We use a new representative survey of Japanese-Brazilians to examine the sustainability of this migration flow. We find both the economic and cultural reasons for emigration to be weakening. Japanese-Brazilians now occupy the upper tiers of the income and occupational distributions in Brazil, and the majority of the third-generation are not participating in many aspects of the Japanese community in Brazil. Moreover, demographic analysis shows that over the next 20 years, the share of migration-age Japanese-Brazilians who are fourth-generation will rise considerably, with such individuals not eligible to migrate under current Japanese immigration law. As a consequence, we predict the rapid growth in the Japanese-Brazilian population in Japan will soon turn to a gradual decline in migrant numbers, and in the long term, erode the stability of this new migration system.