The Empire of Japan's strategy on winning WW2 was based on Alfred Mahan's book "The influence of seapower on history". Basically Mahan and the Japanese who read him believed that a decisive naval battle would decide a naval conflict like the Pacific War. The Japanese also thought that the Americans had no stomach for war and would give up if the casualty rate became high enough. So the Japanese strategy to "win" the war was to occupy lots of places in East Asia and the Pacific while people were occupied with Germany, defeat the Americans in a decisive naval battle and wait for the Americans to negotiate after the soft people living under a democracy admitted they had no stomach for a war. Nazi Germany entered war planning only as a useful distraction for the other powers. Their fall didn't affect Japanese thinking of how to "win" the war. If you look at the Supreme Council's meetings, the Soviets turning around on the Japanese and invading Manchuria had more of an impact than the Nazis falling. Some officials in the Supreme Council still believed the Americans would accept a negotiated peace if the casualties on the invasion of Japan became high enough.