The Japanese bombed Pearl Harbour. This was the first attack on American soil in world war two. Emperor Hirohito knew about the attack for a month before it happened. He and all his officials agreed that America would get involved - so they attacked first. This was an extremely unwise decision. This event triggered a series of battles in the pacific, like the battle of Midway. This also triggered a mass fire bombing of Tokyo. In March 1945 America dropped over a thousand tons of fire bombs on Tokyo. This was a really terrible for the Japanese because most of their structures were made of wood and caught on fire easily. The fire bombs killed more people then the atomic bombs.
The emperor stayed in Tokyo during the bombings, he wanted to endure the same suffering as his people. Ultimately it led to America using atomic bombs on Hiroshima and Nagasaki. The bombs completely destroyed the cities. Thousands of innocent civilians died from these bombs. These tragedies were one of the reasons Hirohito surrendered. There was another reason that the U.S.S.R. declared war on Japan and it was after Germany surrendered. Japan's forces were nearly depleted and he could not let his people die