From the Tokyo Metropolitan Government. People as of October 1, 2025 (estimate). Area as of July 1, 2025.
Tokyo was first called Edo. The city started to grow after Tokugawa Ieyasu set up his government, the Tokugawa Shogunate, there in 1603.
By the middle of the 1700s, Edo had more than a million people. In 1721 the first count of the people found about 1.3 million.
In 1868 the Meiji period began. Edo was renamed Tokyo, and the Emperor moved there from Kyoto.
In 1943, Tokyo Prefecture and Tokyo City were joined to make the Metropolis of Tokyo. The 23 special wards began in 1947.
Today Tokyo has three parts. The 23 special wards have about 9.95 million people. The Tama area (26 cities, 3 towns and 1 village) has about 4.30 million. The islands in the Pacific Ocean, the Izu Islands and the Ogasawara Islands, have about 22,000.
Tokyo covers only 0.6% of Japan’s land, but about 11.6% of Japan’s people live there.
With 6,488 people per square kilometer, Tokyo is the most crowded prefecture in Japan.
There is no single right answer. Talking it over with someone at home is a good way to learn.