According to a 2000 report by the Agency for Cultural Affairs, about 50% of the population practice Shintoism and 44% practice Buddhism. Religious identities are not mutually exclusive, and many Japanese maintain affiliations with both a Buddhist temple and a Shinto shrine.
Shinto, originally concerned with the worship of spirits of nature, grew under the influence of Chinese Confucianism to include worship of family and imperial ancestors, and thus provided the foundation of Japanese social structure. Shinto became an instrument of nationalism after 1868, as the government officially sponsored and subsidized it, requiring that it be taught in the schools and that all Japanese belong to a state Shinto shrine. After World War II, Shinto was abolished as a state religion, and the emperor issued an imperial rescript denying divine origin. Today, Shinto exists as a private religious organization.
Buddhism is considered by some the most important religion in Japan. Introduced through China and Korea around AD 552, Buddhism spread rapidly throughout Japan and has had considerable influence on the nation's arts and its social institutions. There are 13 sects ( shu ) and 56 denominations, the principal shu being Tendai, Shingon, Jodo, Zen, Soto, Obaku, and Nichiren. Japanese Buddhism was founded on the Mahayana school, which emphasizes the attainment of Buddhahood, whereas the Hinayana Buddhism of India emphasizes obedience to commandments and personal perfection. The great temples and gardens of Japan, the famous Japanese tea ceremony ( chanoyu ), and Japanese flower-arranging arts ( ikebana ) owe their development to the influence of Buddhism.
Religions designated as other are practiced by about 6% of the population (including 0.8% practicing Christianity). Christianity, introduced to Japan by the Jesuit St. Francis Xavier in 1549, was first encouraged by feudal lords but then banned in 1613, often under penalty of death. After that time, a unique sect known as "hidden Christians" developed, with no tradition of churches or public displays of faith and a syncretic doctrine that incorporated local ideas and history. The prohibition against Christianity was in force until 1873, following the reopening of Japan to international relations in 1854. Following World War II, when the emperor lost his claim to divinity, some Japanese gave up Shinto and converted to Christianity or Judaism.
After World War II, a considerable number of new religious groups sprouted up. One of these, the Soka-Gakkai, a Buddhist offshoot, controlled a political party ( Komeito ), the third-strongest political group in Japan, until politics and religion were officially separated in 1970. In addition to the established and new religions, Confucianism, an ethical system originating in China, has strongly influenced Japanese society since the earliest periods, providing underpinnings for some characteristically Japanese attitudes.