This is how it was:remember too that they had been fighting for some time now in china and other areas....so their resources were already being taxed. they had to occupy those areas and that takes manpower. they had a population but not enough to meet all their needs. plus their material resources had to be proiritized. yes they could have had the manpower and money but at the cost of something else....
WWII Imperial Japanese Naval Aviation Page
WWII Imperial Japanese Navy Aircraft
"At the beginning of World War II, the Imperial Navy had created the finest naval aviation corps in the world. Japanese aircraft were at least the equals of anything then flying in the West, and in some cases (as with the legendary Zero fighter) were substantially better. Japanese aircrews were superbly trained and had been battle tested in the conflict in China during the late 1930's. When war tore across the Pacific in December 1941, the IJNAF was more than a match for any of its opponents. It is not surprising , then, that Japanese aviators scored victory after stunning victory during the first six months of the war, from the attack on Pearl Harbor, through the sinking of the British men-of-war Prince of Wales and Repulse, to the fearsome raids on northern Australia and the IJN's rampage through the Indian Ocean in April 1942. Only after the defeat at Coral Sea and the debacle at Midway was this force finally able to be engaged on nearly equal terms. Throughout the war, the IJNAF remained a potent weapon, though Japanese equipment was eventually outclassed by newer American models, and relentless attrition began to take its toll on pilot quality. Even in defeat, though, the IJNAF refused to wilt away, finally immolating itself in the form of the Kamikaze air corps." (emphasis supplied)