Who led Japan during World War ll?
Although Japan was under the rule of Emperor Hirohito he was a kind of divine/symbolic figure (in theory) not concerned with earthly matters.
The Prime Ministers of Japan (all of them of the armed forces) were really leading Japan and the war effort.
As Prime Ministers, we had: General Hideki Toyo (from October 17, 1941, to July 22, 1944) followed by General Kuniaki Koiso (from July 22, 1944 to April 7, 1945) and finally Admiral Kantaro Suzuki (from 7 April-17 August 1945).
Toyo was the leader during the attack against Pearl Harbor (the episode that started the war against the US). He was considered the Japanese version of Hitler/Mussolini by the Allies.
When the war started to become really difficult for Japan Toyo simply resigned and Koiso was chosen as a kind of figurehead to let the army going on in its suicidal course of total war.
When the war went even more badly Koiso resigned and was followed by an Admiral of the Navy (up to then considered “dishonored” after all the naval defeats suffered starting from Midway).
Suzuki, basically, managed only to negotiate for peace (risking his life in the process) against the will of the fanatics of the army that wanted to continue the war to win better conditions of peace.
As my personal input I think that the Emperor wasn
t really extraneous to the crucial decisions that led to the war and its disastrous conclusion. After the war, to avoid problems with the population, the Emperor was presented as an innocent bystander that couldnt do anything to avoid or stop the war. In reality after the two nuclear bombings and the declaration of war from the USSR, he IMPOSED the armistice to the army showing that he wasn`t really a simple iconic figure without power!