Toyoda, originally the Commander of the Yokosuka Naval Base, succeeded Admiral KOGA as Commander in Chief of the Combined Navy in March 1943. He was firmly committed to the policy of luring the Americans into the ‘Decisive Battle’ to destroy their entire fleet and had his first attempt at this in June 1944. In May 1944 the Americans had made a landing at Biak and Toyoda believing this to be the main US offensive set Operation Kon into action, which involved transporting troops from the Marianas to Biak. This was unsuccessful and in the meantime the American Central Pacific Fleet attacked the unprepared Marianas. Toyoda therefore ordered operation AGo, which involved luring the American Fleet from near the Marianas to a point near the Palaus. This resulted in the catastrophic Battle of the Philippine Sea in which the Japanese lost over 400 planes, many ships and their last chance to confront the American Navy with equal force.
Toyoda however did not renounce his belief in the ‘Decisive Battle’ which he now planned for Leyte Gulf. This battle, which occurred in October 1944, was well planned by the Japanese and they could have succeeded in inflicting great damage on the US Fleet, but due to bad co-ordination, inflexibility and lack of air power, they lost their last aircraft carriers while inflicting little damage on the Americans. Toyoda ordered the last action of the Japanese Navy in April 1945 when he sent the Yamato on a suicide mission to Okinawa. It was sunk however before it arrived there.
Toyoda was a member of the triumvirate of die-hards (the others were UMEZU and ANAMI) who rejected any form of unconditional surrender, including the Potsdam Declaration. Nonetheless he was able to continue as Navy Chief of Staff after the war.