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.