Chiba Prefecture in the context of "Tobu Railway"

The Greater Tokyo Area is the most populous metropolitan area in the world, consisting of the Kantō region of Japan (including Tokyo Metropolis and the prefectures of Chiba, Gunma, Ibaraki, Kanagawa, Saitama, and Tochigi) as well as the prefecture of Yamanashi of the neighboring Chūbu region. In Japanese, it is referred to by various terms, one of the most common being Capital Region (首都圏, Shuto-ken).

As of 2016, the United Nations estimates the total population at 38,140,000. It covers an area of approximately 13,500 km (5,200 mi), giving it a population density of 2,642 people/km. It is the second-largest single metropolitan area in the world in terms of built-up or urban function landmass at 8,547 km (3,300 mi), behind only the New York City metropolitan area at 11,642 km (4,495 mi). With over US$2 trillion in GDP, Tokyo remains the second-largest metropolitan economy in the world, also behind New York.

Tokyo Bay (東京湾, Tōkyō-wan) is a bay located in the southern Kantō region of Japan spanning the coasts of Tokyo, Kanagawa Prefecture, and Chiba Prefecture, on the southern coast of the island of Honshu. Tokyo Bay is connected to the Pacific Ocean by the Uraga Channel. The Tokyo Bay region is the most populous and the largest industrialized area in Japan.

The Kantō region (関東地方, Kantō Chihō; IPA: [kaꜜn.toː, kan.toː tɕiꜜ.hoː, kan.toː tɕi̥.hoꜜː]) is a geographical region of Honshu, the largest island of Japan. In a common definition, the region includes the Greater Tokyo Area and encompasses seven prefectures: Chiba, Gunma, Ibaraki, Kanagawa, Saitama, Tochigi, and Tokyo. Slightly more than 45 percent of the land area within its boundaries is the Kantō Plain. The rest consists of the hills and mountains that form land borders with other regions of Japan.

As the Kantō region contains Tokyo, the capital and largest city of Japan, the region is considered the center of Japan's politics and economy. According to the official census on October 1, 2010, by the Statistics Bureau of Japan, the population was 42,607,376, amounting to approximately one third of the total population of Japan.

Ibaraki Prefecture (茨城県, Ibaraki-ken; Japanese pronunciation: [i.baꜜ.ɾa.kʲi, i.ba.ɾa.kʲi̥ꜜ.keɴ, i.ba.ɾaꜜ.kʲi̥.keɴ]) is a prefecture of Japan located in the Kantō region of Honshu. Ibaraki Prefecture has a population of 2,828,086 (1 July 2023) and has a geographic area of 6,097.19 square kilometres (2,354.14 square miles). Ibaraki Prefecture borders Fukushima Prefecture to the north, Tochigi Prefecture to the northwest, Saitama Prefecture to the southwest, Chiba Prefecture to the south, and the Pacific Ocean to the east.

Mito, the capital, is the largest city in Ibaraki Prefecture. Other major cities include Tsukuba, Hitachi, and Hitachinaka. Ibaraki Prefecture is located on Japan's eastern Pacific coast to the northeast of Tokyo, and is part of the Greater Tokyo Area, the most populous metropolitan area in the world. Ibaraki Prefecture features Lake Kasumigaura, the second-largest lake in Japan; the Tone River, Japan's second-longest river and largest drainage basin; and Mount Tsukuba, one of the most famous mountains in Japan. Ibaraki Prefecture is also home to Kairaku-en, one of the Three Great Gardens of Japan, and is an important center for the martial art of Aikido.

Kanagawa Prefecture (神奈川県, Kanagawa-ken; Japanese pronunciation: [ka.naꜜ.ɡa.wa, -ŋa.wa, -na.ɡa.waꜜ.keɴ, -ŋa.waꜜ-]) is a prefecture of Japan located in the Kantō region of Honshu. Kanagawa Prefecture is the second-most populous prefecture of Japan at 9,221,129 (1 April 2022) and third-densest at 3,800 inhabitants per square kilometre (9,800/sq mi). Its geographic area of 2,415 km (932 sq mi) makes it fifth-smallest. Kanagawa Prefecture borders Tokyo to the north, Yamanashi Prefecture to the northwest and Shizuoka Prefecture to the west.

Yokohama is the capital and largest city of Kanagawa Prefecture and the second-largest city in Japan, with other major cities including Kawasaki, Sagamihara, and Fujisawa. Kanagawa Prefecture is located on Japan's eastern Pacific coast on Tokyo Bay and Sagami Bay, separated by the Miura Peninsula, across from Chiba Prefecture on the Bōsō Peninsula. Kanagawa Prefecture is part of the Greater Tokyo Area, the most populous metropolitan area in the world, with Yokohama and a number of its cities being major commercial hubs and southern suburbs of Tokyo. Kanagawa Prefecture was the political and economic center of Japan during the Kamakura period when Kamakura was the de facto capital and largest city of Japan as the seat of the Kamakura shogunate from 1185 to 1333. Kanagawa Prefecture is a popular tourist area in the Tokyo region, with Kamakura and Hakone being two popular side trip destinations.

Saitama Prefecture (埼玉県, Saitama-ken; Japanese pronunciation: [saꜜi.ta.ma, sai.ta.maꜜ.keɴ]) is a landlocked prefecture of Japan located in the Kantō region of Honshu. Saitama Prefecture has a population of 7,338,536 (January 1, 2020) and has a geographic area of 3,797 km (1,466 sq mi). Saitama Prefecture borders Tochigi Prefecture and Gunma Prefecture to the north, Nagano Prefecture to the west, Yamanashi Prefecture to the southwest, Tokyo to the south, Chiba Prefecture to the southeast, and Ibaraki Prefecture to the northeast.

Saitama is the capital and largest city of Saitama Prefecture, with other major cities including Kawaguchi, Kawagoe, and Tokorozawa.

36°00′N 140°00′E / 36.000°N 140.000°E / 36.000; 140.000

The Kantō Plain (Japanese: 関東平野, Hepburn: Kantō heiya), in the Kantō region of central Honshu, is the largest plain in Japan. Its 17,000 km covers more than half of the region extending over Tokyo, Saitama Prefecture, Kanagawa Prefecture, Chiba Prefecture, Gunma Prefecture, Tochigi Prefecture, and Ibaraki Prefecture.

The Great Kantō Earthquake (Japanese: 関東大地震, romanized: Kantō daijishin or 関東大震災, Kantō daishinsai) was a megathrust earthquake that struck the Kantō Plain on the main Japanese island of Honshu at 11:58:32 JST (02:58:32 UTC) on Saturday, 1 September 1923. It had an approximate magnitude of 8.0 on the moment magnitude scale (M_w), with its epicenter located some 100 km (62 mi) southwest of the capital Tokyo. The earthquake devastated Tokyo, the port city of Yokohama, and surrounding prefectures of Kanagawa, Chiba, and Shizuoka, and caused widespread damage throughout the Kantō region.

The event was a complex disaster, with modern research indicating it consisted of three consecutive shocks in the span of several minutes. The initial megathrust event in Kanagawa Prefecture was followed three minutes later by a magnitude 7.2 earthquake centered beneath Tokyo Bay, and two minutes after that by a magnitude 7.3 shock in Yamanashi Prefecture. Fires, exacerbated by strong winds from a nearby typhoon, spread rapidly through the densely populated urban areas, accounting for the majority of the devastation and casualties. The death toll is estimated to have been between 105,000 and 140,000 people, including tens of thousands who went missing and were presumed dead. Over half of Tokyo and nearly all of Yokohama were destroyed, leaving approximately 2.5 million people homeless. The disaster triggered widespread social unrest, including the Kantō Massacre, in which ethnic Koreans and others mistaken for them were murdered by vigilante groups based on false rumors.

The Bōsō Peninsula (房総半島, Bōsō-hantō) is a peninsula that encompasses the entirety of Chiba Prefecture on Honshu, the largest island of Japan. It is part of the Greater Tokyo Area. It forms the eastern edge of Tokyo Bay, separating it from the Pacific Ocean. The peninsula covers approximately 5,034 square kilometres (1,944 sq mi).