Shikoku (四国, literally "four provinces") is one of the four main islands of Japan. Shikoku is the smallest (225 km or 139.8 mi long and between 50 and 150 km or 31.1 and 93.2 mi wide) and least populous (3.8 million as of 2015, 3.1%) of the main islands, located south of Honshu and east of Kyushu