Since 2005, Japan, South Korea, and Taiwan have competed with each other for the less-than-desirable distinction of having the world’s fastest aging population, lowest birthrate, and most rapidly shrinking workforce. While maintaining relatively restrictive immigration policies toward labor migration, government officials in all three countries have proactively recruited female migrants for one specific national shortage: marriage partners for the growing numbers of unmarried men largely in rural areas. As a result, migrant women married to native citizens, known as “marriage migrants,” have become one of the fastest-growing immigrant groups in each country. I argue that gendered migration has challenged long-held conceptions of blood-based belonging and membership in each country and subsequently created a political opening for policy reform. In particular, the fit between civic legacies in each country – emerging from previous efforts to incorporate Korean residents in Japan, women in Korea, and indigenous populations in Taiwan – and the concerns of migrant women and their bicultural children gave advocacy efforts for this population added urgency and political capital.