Editor's note: In its report on the explosion at a US military base in Japan, Reuters says the blast occurred just after midnight local time at the Sagami Depot, an Army post in Sagamihara, 25 miles southwest of Tokyo. - Tom
Tokyo(東京,Tōkyō, "Eastern Capital") (Japanese: [toːkjoː], English /ˈtoʊki.oʊ/), officially Tokyo Metropolis(東京都,Tōkyō-to), is one of the 47 prefectures of Japan, and is both the capital and largest city of Japan. The Greater Tokyo Area is the most populous metropolitan area in the world. It is the seat of the Emperor of Japan and the Japanese government. Tokyo is in the Kantō region on the southeastern side of the main island Honshu and includes the Izu Islands and Ogasawara Islands. Formerly known as Edo, it has been the de facto seat of government since 1603 when Shogun Tokugawa Ieyasu made the city his headquarters. It officially became the capital after Emperor Meiji moved his seat to the city from the old capital of Kyoto in 1868; at that time Edo was renamed Tokyo. Tokyo Metropolis was formed in 1943 from the merger of the former Tokyo Prefecture (東京府,Tōkyō-fu) and the city of Tokyo (東京市,Tōkyō-shi).
Tokyo is often referred to and thought of as a city, but is officially known and governed as a "metropolitan prefecture", which differs from and combines elements of both a city and a prefecture; a characteristic unique to Tokyo. The Tokyo metropolitan government administers the 23 Special Wards of Tokyo (each governed as an individual city), which cover the area that was formerly the City of Tokyo before it merged and became the subsequent metropolitan prefecture in 1943. The metropolitan government also administers 39 municipalities in the western part of the prefecture and the two outlying island chains. The population of the special wards is over 9 million people, with the total population of the prefecture exceeding 13 million. The prefecture is part of the world's most populous metropolitan area with upwards of 37.8 million people and the world's largest urban agglomeration economy. The city hosts 51 of the Fortune Global 500 companies, the highest number of any city in the world. Tokyo ranked third in the International Financial Centres Development IndexEdit. The city is also home to various television networks like Fuji TV, Tokyo MX, TV Tokyo, TV Asahi, Nippon Television, NHK and the Tokyo Broadcasting System.
Tokyo ranked third in the Global Economic Power Index and fourth in the Global Cities Index. The city is considered an alpha+ world city—as listed by the GaWC's 2008 inventory—and in 2014, Tokyo was ranked first in the "Best overall experience" category of TripAdvisor's World City Survey (the city also ranked first in the following categories: "Helpfulness of locals", "Nightlife", "Shopping", "Local public transportation" and "Cleanliness of streets"). In 2015, Tokyo was ranked as the 11th most expensive city for expatriates, according to the Mercer consulting firm, and also the world's 11th most expensive city, according to the Economist Intelligence Unit's cost-of-living survey. In 2015 Tokyo was named the Most Liveable City in the world by the magazine Monocle. The Michelin Guide has awarded Tokyo by far the most Michelin stars of any city in the world. Tokyo ranked first in the world in the Safe Cities Index. Tokyo hosted the 1964 Summer Olympics, the 1979 G-7 summit, the 1986 G-7 summit, and the 1993 G-7 summit, and will host the 2020 Summer Olympics and the 2020 Summer Paralympics.