Japan's population is estimated at around 126 million, with 80% of the population living on Honshū. Due to the rugged and mountainous terrain with 66% forest, the population is clustered in urban areas on the coast, plains and valleys. Japan is an urban society with only 5% of the labor force working in agriculture. About 80 million of the urban population is heavily concentrated on the Pacific coast of Honshu. In 2010, 90.7% of the total Japanese population lived in cities.
The capital city Tokyo has a population of 13.8 million (2018). It is part of the Greater Tokyo Area, the biggest metropolitan area in the world with 38,140,000 people (2016). The area is 13,500 km2 (5,200 sq mi) and has a population density of 2,642 square kilometres (1,020 sq mi).
Japanese society is linguistically, ethnically and culturally homogeneous, composed of 98.5% ethnic Japanese, with small populations of foreign workers. Zainichi Koreans, Chinese, Filipinos, Brazilians mostly of Japanese descent, Peruvians mostly of Japanese descent and Americans are among the small minority groups in Japan. In 2003, there were about 134,700 non-Latin American Western (not including more than 33,000 American military personnel and their dependents stationed throughout the country) and 345,500 Latin American expatriates, 274,700 of whom were Brazilians (said to be primarily Japanese descendants, or nikkeijin, along with their spouses), the largest community of Westerners.
, an ethnic minority people from Japan
The most dominant native ethnic group is the Yamato people; primary minority groups include the indigenous Ainu and Ryukyuan people, as well as social minority groups like the burakumin. There are persons of mixed ancestry incorporated among the Yamato, such as those from Ogasawara Archipelago. In 2014, foreign-born non-naturalized workers made up only 1.5% of the total population. Japan is widely regarded as ethnically homogeneous, and does not compile ethnicity or race statistics for Japanese nationals; sources varies regarding such claim, with at least one analysis describing Japan as a multiethnic society while another analysis put the number of Japanese nationals of recent foreign descent to be minimal. Most Japanese continue to see Japan as a monocultural society. Former Japanese Prime Minister and current Finance Minister Tarō Asō described Japan as being a nation of "one race, one civilization, one language and one culture", which drew criticism from representatives of ethnic minorities such as the Ainu.
Japan has the second longest overall life expectancy at birth of any country in the world: 83.5 years for persons born in the period 2010–2015. The Japanese population is rapidly aging as a result of a post–World War II baby boom followed by a decrease in birth rates. In 2012, about 24.1 percent of the population was over 65, and the proportion is projected to rise to almost 40 percent by 2050.
On September 15, 2018, for the first time, 1 in 5 persons in Japan is 70 or older according to the Ministry of Internal Affairs and Communications. 26.18 million people are 70 or older and accounted for 20.7 percent of the population. Elderly women crossed the 20 million line at 20.12 million, substantially outnumbering the nation's 15.45 million elderly men.
Japan has full religious freedom based on Article 20 of its Constitution. Upper estimates suggest that 84–96 percent of the Japanese population subscribe to Shinto as its indigenous religion (50% to 80% of which considering degrees of syncretism with Buddhism, shinbutsu-shūgō). However, these estimates are based on people affiliated with a temple, rather than the number of true believers. The number of Shinto shrines in Japan is estimated to be around 100,000. Other studies have suggested that only 30 percent of the population identify themselves as belonging to a religion. According to Edwin Reischauer and Marius Jansen, some 70–80% of the Japanese do not consider themselves believers in any religion. Nevertheless, the level of participation remains high, especially during festivals and occasions such as the first shrine visit of the New Year. Taoism and Confucianism from China have also influenced Japanese beliefs and customs. Japanese streets are decorated on Tanabata, Obon and Christmas.
Shinto is the largest religion in Japan, practiced by nearly 80% of the population, yet only a small percentage of these identify themselves as "Shintoists" in surveys. This is due to the fact that "Shinto" has different meanings in Japan: most of the Japanese attend Shinto shrines and beseech kami without belonging to Shinto organisations, and since there are no formal rituals to become a member of folk Shinto, Shinto membership is often estimated counting those who join organised Shinto sects. Shinto has 100,000 shrines and 78,890 priests in the country. Buddhism first arrived in Japan in the 6th century; it was introduced in the year 538 or 552 from the kingdom of Baekje in Korea.
Christianity was first introduced into Japan by Jesuit missions starting in 1549. Today, fewer than 1% to 2.3% are Christians,[note 2] most of them living in the western part of the country, where the missionaries' activities were greatest during the 16th century. Nagasaki Prefecture has the highest percentage of Christians: about 5.1% in 1996. As of 2007 , there are 32,036 Christian priests and pastors in Japan. Throughout the latest century, some Western customs originally related to Christianity (including Western style weddings, Valentine's Day and Christmas) have become popular as secular customs among many Japanese.
Islam in Japan is estimated to constitute, about 80–90%, of foreign born migrants and their children, primarily from Indonesia, Pakistan, Bangladesh, and Iran. Much of the ethnic Japanese Muslims are those who convert upon marrying immigrant Muslims. The Pew Research Center estimated that there were 185,000 Muslims in Japan in 2010.
Other minority religions include Hinduism, Sikhism and Judaism, Bahá'í Faith, and since the mid-19th century numerous new religious movements have emerged in Japan.
More than 99 percent of the population speaks Japanese as their first language. Japanese is an agglutinative language distinguished by a system of honorifics reflecting the hierarchical nature of Japanese society, with verb forms and particular vocabulary indicating the relative status of speaker and listener. Japanese writing uses kanji (Chinese characters) and two sets of kana (syllabaries based on cursive script and radical of kanji), as well as the Latin alphabet and Arabic numerals.
Besides Japanese, the Ryukyuan languages (Amami, Kunigami, Okinawan, Miyako, Yaeyama, Yonaguni), also part of the Japonic language family, are spoken in the Ryukyu Islands chain. Few children learn these languages, but in recent years the local governments have sought to increase awareness of the traditional languages. The Okinawan Japanese dialect is also spoken in the region. The Ainu language, which has no proven relationship to Japanese or any other language, is moribund, with only a few elderly native speakers remaining in Hokkaido. Public and private schools generally require students to take Japanese language classes as well as English language courses.
The changes in demographic structure have created a number of social issues, particularly a potential decline in workforce population and increase in the cost of social security benefits such as the public pension plan. A growing number of younger Japanese are not marrying or remain childless. In 2011, Japan's population dropped for a fifth year, falling by 204,000 people to 126.24 million people. This was the greatest decline since at least 1947, when comparable figures were first compiled. This decline was made worse by the March 2011 earthquake and tsunami, which killed nearly 16,000 people.
Japan's population is expected to drop to 95 million by 2050; 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 ageing population. Japan accepts an average flow of 9,500 new Japanese citizens by naturalization per year. According to the UNHCR, in 2012 Japan accepted just 18 refugees for resettlement, while the United States took in 76,000.
Japan suffers from a high suicide rate. In 2009, the number of suicides exceeded 30,000 for the twelfth successive year. Suicide is the leading cause of death for people under 30.