Rule of Japan during WWII was bizarre, in that even though the Emperor, Hirohito, was supposed to be absolute ruler, most of the time he was really more of a symbol than an actual leader. He only seemed to exert significant overt power in a few, select situations, but most of the time preferring to just be a rubber stamp for whatever the leaders of the Imperial Japanese High Command (IJHC) wanted, since they promised him that everything they did would be all to his glory--that way he could spend most of his time puttering around tide pools and aquariums (he was an avid marine biologist). The IJHC was a "committee" of mostly army generals, that through most of the war, was dominated by General and Prime Minister Hideki Tojo until Tojo was forced to resign after the fall of Saipan in June, 1944. He was replaced as Prime Minister by General Koniaki Koiso. Interestingly, the Emperor did play a large role in ousting Tojo, because he was unhappy with the fall of Saipan, and he expressed disdain for Tojo's bullsh*t excuses and outrageous claims of impending "victory." The emperor would ask his generals, "if we are winning every battle, then how is it possible that all these "decisive victories" keep happening closer and closer to Japan?"
Although the Emperor was "officially" a living god and absolute ruler, her aggressive expansionism which precipitated the war was instigated by hothead nationalist Army officers, and early on during the 1930s, it was lower ranking officers in the field in China who started sh*t completely independent of any control from Tokyo, then basically telling their commanders back home, "ok, we started it, now you have to support us--and if you don't, then you are traitors to the Emperor." It was a truly weird situation, in which the entire chain of command was turned upside down.