Tokyo is Japan's capital and the world's most populous metropolis. It is also one of Japan's 47 prefectures, consisting of 23 central city wards and multiple cities, towns and villages.
Prior to 1868, Tokyo was known as Edo. A small castle town in the 16th century, Edo became Japan's political center in 1603 when Tokugawa Ieyasu established his feudal government there. A few decades later, Edo had grown into one of the world's most populous cities. With the Meiji Restoration of 1868, the emperor and capital moved from Kyoto to Edo, which was renamed Tokyo ("Eastern Capital"). Large parts of Tokyo were destroyed in the Great Kanto Earthquake of 1923 and in the air raids of 1945.

Shinjuku is one of the 23 city wards of Tokyo, but the name commonly refers to just the large entertainment, business and shopping area around Shinjuku Station.
Shinjuku Station is the world's busiest railway station, handling more than two million passengers every day. It is served by about a dozen railway and subway lines.
West of the station is Shinjuku's skyscraper district, home to many of Tokyo's tallest buildings, including several premier hotels and the twin towers of the Metropolitan Government Office, whose observation decks are open to the public for free.
Northeast of the station lies Kabukicho, Japan's largest and wildest red light district, while department stores, subterranean malls and electronic shops surround Shinjuku Station on all four sides, including the recently redeveloped Southern Terrace.

Located between the Imperial Palace and Tokyo Station, Marunouchi is one of Japan's most prestigious business districts. During the Edo Period, Marunouchi (literally "within the enclosure") was located within the outer moats of Edo Castle and contained the residences of some of Japan's most powerful feudal lords. Together with neighboring Otemachi, Marunouchi is now home to the headquarters of many of Japan's most powerful companies, particularly from the financial sector.

Nihonbashi (Japan Bridge) is a city district of Tokyo, just north of Ginza and northeast of Marunouchi and Tokyo Station. The bridge, after which the district is named, has been the kilometer zero marker for Japan's national highway network since the early Edo Period.
Formerly a wooden bridge, the Nihonbashi was reconstructed in stone during the Meiji Period, and was covered by an expressway in the 1960s.
As the "center of Japan", the Nihonbashi district has enjoyed much commercial prosperity over the centuries, and the area has flourished with bustling shops lining the streets and shipping canals (most of which have been filled in in the meantime). Many shops with centuries-long histories are still operating in the district today and make for pleasant scrolls. During the Edo Period (1600-1867), the Mitsui family, one of the most powerful merchant families, opened a highly successful textile shop, the Echigoya, in Nihonbashi. Its successor, the Mitsukoshi Nihonbashi, became Japan's first department store and still stands in the district's center.

Asakusa is the center of Tokyo's shitamachi (literally "low city"), one of Tokyo's districts, where an atmosphere of the Tokyo of past decades survives.
Asakusa's main attraction is Sensoji, a very popular Buddhist temple, built in the 7th century.
For many centuries, Asakusa used to be Tokyo's leading entertainment district. During the Edo Period (1603-1867), when the district was still located outside the city limits, Asakusa was the site of kabuki theaters and a large red light district. In the late 1800s and early 1900s, modern types of entertainment, including movie theaters, set foot in Asakusa.
However, large parts of Asakusa were destroyed in the air raids of World War Two. And while the area around the rebuilt Sensoji has regained its former popularity after the war, the same cannot be said for Asakusa's entertainment district.

Sensoji ("Senso" is an alternative reading for Asakusa and "ji" means