Battle of Dan-no-ura
Manju Shima 満珠島 "tide-flowing jewel island" and Kanju Shima 干珠島 "tide-ebbing jewel island" are uninhabited islets in the Kanmon Straits near Chōfu 長府 in Shimonoseki, Yamaguchi. In the 1185 CE Battle of Dan-no-ura during the Genpei War, the Minamoto (Genji) fleet defeated the Taira (Heike) fleet by taking advantage of the tides around these two islands. In 1943, the "Manju maru" 満珠丸 and "Kanju maru" 干珠丸 Etorofu class coastal defense ships were named after the tide-jewel islands.