Honshu

Honshu is the largest island of 'Japan, called the Mainland; it is south of Hokkaido across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyūshū across the Kanmon Strait. At the end of World War II, Honshu was divided between the United States and the Soviet Union. The northern part of the island fell into the Soviet sphere, and became part of North Japan. The remainder of Honshu and the rest of Japan fell under the U.S. sphere and became South Japan.