Situated off the eastern edge of the Asian continent, the Japanese archipelago is bounded on the N by the Sea of Okhotsk, on the E and S by the Pacific Ocean, on the SW by the East China Sea, and on the W by the Sea of Japan / East Sea. The total area of Japan is 377,835 sq km (145,883 sq mi). Comparatively, the area occupied by Japan is slightly smaller than the state of California. It extends 3,008 km (1,869 mi) NE – SW and 1,645 km (1,022 mi) SE – NW and has a total coastline of 29,751 km (18,486 mi).
The five districts are Honshu, Hokkaido, Kyushu, Shikoku, and Okinawa. Each of the five districts consists of a main island of the same name and hundreds of surrounding islands.
Of the thousands of lesser islands, four are of significance: Tsushima, in the straits between Korea and Japan; Amami Oshima, of the northern Ryukyu Islands at the southern end of the Japanese archipelago; Sado Island in the Sea of Japan / East Sea off central Honshu; and Awaji Island, lying between Shikoku and Honshu. Two groups of islands returned to Japan by the United States in 1968 are located some 1,300 km (800 mi) due east of the Ryukyus: the Ogasawara (Bonin) Islands, about 885 km (550 mi) south of Tokyo, and the Kazan (Volcano) Islands, directly south of the Ogasawara group.
Japan's principal island is Honshu, on which are located the capital city of Tokyo, the principal cities and plains, and the major industrial areas. This island is divided into five regions: Tohoku, from north of Kanto to Tsugaru Strait; Kanto, embracing seven prefectures in the Tokyo-Yokohama region; the Chubu, or central, region, from west of Tokyo to the Nagoya area; Kinki, including the important cities of Kyoto, Osaka, Kobe, and Nara; and Chugoku, a narrow peninsula thrusting westward from Kinki between the Sea of Japan / East Sea and the Inland Sea, which lies between southern Honshu and the island of Shikoku.
The Japanese government maintains that the Habomai island group and Shikotan, lying just off Hokkaido and constituting fringe areas of the Kurils, belong to Japan and should be returned to Japanese administration. These islands and the Kuril Islands are currently occupied by Russia, whose claims are not formally recognized by Japan.
Japan's capital city, Tokyo, is located on the east coast of the island of Honshu.