, also known as Operation Heaven One (or Ten-ichi-gō 天一号), was the last major Japanese naval operation in the Pacific Theater of World War II. The resulting engagement is also known as the Battle of the East China Sea. In April 1945, the , the largest battleship in the world, and nine other Japanese warships, embarked from Japan for a suicide attack on Allied forces engaged in the Battle of Okinawa. The Japanese force was attacked by U.S. carrier-borne aircraft before it could reach Okinawa. Yamato and five other Japanese warships were sunk. The battle demonstrated U.S. air supremacy in the Asiatic-Pacific Theater and the vulnerability of surface ships without air cover to aerial attack. The battle also exhibited Japan's willingness to make extreme sacrifices in kamikaze attacks aimed at slowing the Allied advance on the Japanese home islands. Background By early 1945, following the Solomon Islands campaign, the Battle of the Philippine Sea and the Battle of Leyte Gulf, the once-formidable Imperial Japanese Navy's Combined Fleet was reduced to just a handful of operational warships and a few remaining aircraft and aircrew. Most of the remaining Japanese warships in the Combined Fleet were stationed at ports in Japan, with most of the large ships at the port of Kure in the Hiroshima Prefecture on the main Japanese island of Honshu. As a final step before the planned invasion of the Japanese home islands, Allied forces invaded Okinawa on 1 April 1945. In March, when briefing Emperor Hirohito on Japan's response to the expected invasion of Okinawa, Japanese military leaders explained that the Imperial Japanese Army was planning extensive air attacks, including the use of kamikaze tactics. The emperor then reportedly asked, "But what about the Navy? What are they doing to assist in defending Okinawa? Have we no more ships?" Now feeling pressured by the emperor to also mount some kind of attack, Japanese Navy commanders conceived a kamikaze-type mission for their remaining operational large ships, which included the battleship . The resulting plan—drafted under the direction of the Commander-in-Chief of the Combined Fleet, Admiral Soemu Toyoda,—called for Yamato and her escorts to attack the U.S. fleet supporting the U.S. troops landing on the western coast of Okinawa. Yamato and her escorts were to fight their way to Okinawa and then beach themselves between Higashi and Yomitan and fight as shore batteries until they were destroyed. Once the ships