Ethnicity plays an increasingly salient role in shaping and regulating international migration. Apart from Japan, many countries, including Italy, Spain, Greece, Korea and Germany, have implemented a descent-based immigration policy, providing ‘co-ethnics’ with privileges, ranging from automatic citizenship to special language training1 (Ministry of Justice, 1992; Thränhardt, 1999). For industrial countries experiencing large inflows of immigrants today, descent-based immigration policy is indeed an effective tool to cope with their need to simultaneously incorporate and selectively control foreign in-migration. It is particularly so in a country, such as Japan, where a sense of ‘blood ties’ is fundamental to nationhood. When the new ethnicity-based immigration provision was introduced in 1990 targeting Japanese descendants, neither the Japanese public nor the international community debated or protested against it. Consistent with the country’s descent-based nationality law, as well as the widespread belief in racial and cultural homogeneity, such a policy made sense.