Admiral Soemu Toyoda (1885-1957) was the commander-in-chief of the Japanese Combined Fleet during the crushing defeats in the battles of the Philippine Sea and Leyte Gulf (both 1944), where his desire for a 'decisive battle' played a part in both defeats.
Toyoda graduated from the Japanese Naval Academy in 1905 and by the time the Japanese entered the Second World War had risen to the rank of full Admiral (September 1941). He was commander of the Kure Naval Station at the time of Pearl Harbor, became part of the Supreme War Council in November 1942 and in May 1943 became commander of the Yokosuka Naval Base. He was considered to be brilliant but sarcastic, and rather difficult to work with.
On 5 May 1944 he was appointed as commander-in-chief of the Combined Fleet, replacing Admiral Mineichi Koga, who had gone missing while flying from Palau to Davao on 31 March 1944. Koga had been planning for a 'decisive battle' in which the massive Japanese battleships could inflict a heavy defeat on the American fleets (for most of the war the Japanese overestimated the amount of damage they were doing to the American fleet and thus believed that the two fleets were much closer in size than they really were). Kurita took Koga's 'Plan Z' and modified it to produce 'A-Go'. This plan was followed by Admiral Ozawa at the battle of the Philippine Sea (19-20 June 1944) and resulting in a crushing Japanese defeat that saw the loss of most of their skilled naval aviators.
Despite this defeat Toyoda retained his belief in the 'decisive battle', this time to be fought either at the Philippines or Formosa, depending on the next American move. The 'Victory' or 'Sho' plans each involved bringing together the surface fleet based close to Singapore and the fuel supplies and the carrier fleet, based in the Inland Sea of Japan where new carrier air groups were forming.
Toyoda played a major part in the defeat of his own plan. When the Americans raided Okinawa and Formosa in prepration for the landing on Leyte Toyoda believed that the invasion had begun and issued the preliminary 'Sho' orders. By chance he was present on Formosa, and believed the exaggerated reports of success from his inexperienced pilots. Believing that the American fleet had been badly damaged Toyoda kept on feeding aircraft in the battle. A massive air battle developed off Formosa (12-16 October 1944) in which the Japanese lost 600 aircraft, including many that had been allocated to the carrier fleet. As a result the carrier force could only act as a decoy during the battle of Leyte Gulf (23-26 October 1944), and the Japanese surface forces were left exposed to American air attack. The battle ended as a second crushing Japanese defeat, this time with the loss of four carriers and three battleships.
Toyoda remained commander of the Combined Fleet after the defeat at Leyte Gulf. His last major operation was the suicidal mission of the battleship Yamato in April 1945. The battleship was ordered to sail to Okinawa where it could beach itself to become a massive gun battery. Instead it was sunk on the first day after leaving Japan.
On 20 May 1945 Toyoda became Navy Chief of Staff. In the last days of the war he was one of the main opponents of Emperor Hirohito's plan to surrender, and indeed to any other attempt to negotiate a peace. He also refused to take part in the surrender ceremony in Tokyo Bay. After the war he cooperated with the American naval historian S.E. Morrison during the production of the epic fifteen volume History of United States Naval Operations in World War II.