Seto Inland Sea
The Seto Inland Sea, also known as Setouchi or often shortened to Inland Sea, is the body of water separating Honshū, Shikoku, and Kyūshū, three of the five main islands of Japan. The region that includes the Seto Inland Sea and the coastal areas of Honshū, Shikoku, and Kyūshū is known as the Setouchi Region.