Shikoku , Japanese pronunciation: [ɕikokɯ] is the smallest of the four main islands of Japan. It is 300 km or 186.4 mi long and between 50 and 150 km or 31.1 and 93.2 mi at its widest. It has a population of 3.8 million, the least populated out of Japan's four main islands. It is south of Honshu and northeast of Kyushu. Shikoku's ancient names include Iyo-no-futana-shima (伊予之二名島), Iyo-shima (伊予島), and Futana-shima (二名島), and its current name refers to the four former provinces that make up the island: Awa, Tosa, Sanuki, and Iyo.

Japan is an island country in East Asia. It is in the northwest Pacific Ocean and is bordered on the west by the Sea of Japan, extending from the Sea of Okhotsk in the north toward the East China Sea, Philippine Sea, and Taiwan in the south. Japan is a part of the Ring of Fire, and spans an archipelago of 14,125 islands, with the five main islands being Hokkaido, Honshu, Shikoku, Kyushu, and Okinawa. Tokyo is the country's capital and largest city, followed by Yokohama, Osaka, Nagoya, Sapporo, Fukuoka, Kobe, and Kyoto.