Japan's population is estimated at around 127.3 million. Japanese society is linguistically and culturally homogeneous with small populations of foreign workers. Zainichi Koreans, Zainichi Chinese, Filipinos, Japanese Brazilians, Japanese Peruvians are amongst the small minorities resident in Japan.? In 2003, there were about 136,000 Western expatriates in Japan. The most dominant native ethnic group is the Yamato people; the primary minority groups include the indigenous Ainu and Ryukyuan, as well as social minority groups like the burakumin.

Japan has one of the highest life expectancy rates in the world, at 81.25 years of age as of 2006. The Japanese population is rapidly aging, the effect of a post-war baby boom followed by a decrease in births in the latter part of the twentieth century. In 2004, about 19.5% of the population was over the age of 65.

The changes in the demographic structure have created a number of social issues, particularly a potential decline in the workforce population and increases in the cost of social security benefits such as the public pension plan. Many Japanese youth are increasingly preferring not to marry or have families as adults.? Japan's population is expected to drop to 100 million by 2050 and to 64 million by 2100. Demographers and government planners are currently in a heated debate over how to cope with this problem. Immigration and birth incentives are sometimes suggested as a solution to provide younger workers to support the nation's aging population.