Japan recently joined a group of nations hosting a substantial number of international migrants. A United Nations (2005) report shows that Japan was one of twenty countries with the largest cumulative number of international migrants between 1990 and 2005. Japan did not belong to this group in 1990. The number of immigrants accepted into Japan in 2005 was larger than those in some European countries such as Switzerland and the Netherlands (United Nations 2006). Immigrants to Japan are expected to increase over the next four decades (Ono and Ono, forthcoming). In order to sustain its economy while overcoming the challenges posed by the rapidly aging society and low fertility, Japan may have little choice but to accept more immigrants (United Nations 2005). The most recent estimates from the United Nations (2005) demonstrate that, in order to sustain its population, Japan would need 381,000 immigrants per year between 2005 and 2050. When immigrant incorporation is accomplished at this rate, foreign born persons are estimated to compose 17.7 percent of the population in Japan in 2050, a level more than 10 times higher than the current level of 1.2 percent (Ministry of Health, Labor and Welfare 2005).