The Haneji Inland Sea is sometimes referred to as a small version of the Japanese Inland Sea, that scenic waterway between the main islands of Japan. The Haneji Inland Sea is located between the eastern side of Motobu Peninsula and the main body of okinawa. The view from Mount Arashi on the peninsular side of the inland sea is a spectacular one whose vista covers Kouri and Yagaji Islands and a number of uninhabited islets. On these small bodies of land Ryukyu Pine Trees, azaleas and lilies grow undisturbed. Spring is a good time for motorists and cyclists to enjoy peaceful and natural scenes.

The Haneji Inland Sea is usually calm, so boating and fishing are popular. Plenty of kisu, a type of small fish, can be taken by fishermen. During the typhoon season, many ships gather in the waters to take harbor against the strong winds.

Almost at the tip of Motobu Peninsula on the western side of the inland sea is the port of Unten. The story of how it got its name is derived from the mighty samurai Minamoto no Tametomo. After losing a battle to gain power in mainland Japan, Minamoto barely escaped. He left his fate(un) to the heavens (ten) and finally arrived at this place in okinawa. Unten Port was involved in other historical events. In 1609, the warriors of Satsuma in Kyushu arrived to initiate the subjugation with the Keicho Incident during the Ryukyu Kingdom Era, and Commodore Perrys naval fleet also visited the port in 1853.