The U.S. government estimates the total population at 125.5 million (midyear 2020 estimate). A report by the Agency for Cultural Affairs (ACA) indicates that membership in religious groups totaled 183 million as of December 31, 2019. This number, substantially more than the country’s population, reflects many citizens’ affiliation with multiple religions. For example, it is common for followers of Buddhism to participate in religious ceremonies and events of other religions, such as Shinto, and vice versa. According to the ACA, the definition of follower and the method of counting followers vary with each religious organization. Religious affiliation includes 88.9 million Shinto followers (48.6 percent), 84.8 million Buddhists (46.3 percent), 1.9 million Christians (1 percent), and 7.4 million adherents of other religious groups (4 percent). The category of “other” and nonregistered religious groups includes Islam, the Baha’i Faith, Hinduism, and Judaism. The indigenous Ainu people mainly practice an animist faith and mostly reside in the northern part of Honshu, in Hokkaido, and in smaller numbers in Tokyo.

Most immigrants and foreign workers practice religions other than Buddhism or Shinto, according to an NGO in close contact with foreign workers. A scholar estimates as of 2018, there are 157,000 non-Japanese Muslims and 43,000 Japanese Muslims in the country, an increase of nearly 60,000 from previous estimates from 2013. He attributed the increase to more non-Japanese Muslims holding permanent residency, marriages between non-Japanese Muslims and Japanese converts to Islam, and their children. Most of the approximately 350 Rohingya Muslims in the country live in Gunma Prefecture, north of Tokyo, with some of them residing in Saitama, Chiba, and Tokyo, according to Burmese Rohingya Association in Japan (BRAJ) President Zaw Min Htut. Ilham Mahmut, the JUA honorary chairman and World Uyghur Congress Representative for East Asia and the Pacific, said most of the 2,000 to 3,000 Uyghur Muslims in the country reside in Tokyo or its surrounding prefectures of Chiba, Saitama, and Kanagawa. The total Jewish population is approximately 3,000 to 4,000, according to a long-term Jewish resident.