So pre-WW2, for a thousand years, the emperor and his family were the very essence of the kami, descended into the flesh. The children of Ameratsu (the sun goddess). The emperors were certainly not a god as Western philosophy views it, but they were definitely more gods than not.
Hirohito dragged the nation into WW2 saying that it was Divine Will that Nihon expand her influence. And for a long while, the nations surrounding Japan were unable to make anybody think that there might be some question of whether God's will was right here or not- Manchuria was the only real hardship, 'till the US started to get busy across the Pacific. Then BLAMMO BLAMMO: two unholy weapons above and beyond anything that anybody could've imagined- two little point singularities of roiling plasma-phase hydrogen, and uranium spitting death into the lives of a good hundred thousand or more.
This is, obviously, not good.
Neal Stephenson makes the point, in the book Cryptonomicon, that to be a good Japanese, you HAD to go do the emperor's will. And the emperor's will suddenly started looking mightily fishy. Really rather... fallible. Which gods aren't supposed to be.
When Japan surrendered to the US, the emperor had to renounce his kami-hood: he's just a guy like you or I, as far as the state religon holds now (well, not the state religion anymore: after post-war mop-up, it's now the indigenous religion). Now, this upheaval is often represented, in Western literature, as a hardship- a horrifying overturn of the social order, a complete destruction of all things that were uniquely Japanese.
...it might have been for Japan's best to say 'Okay, that guy we were following around doing all this crazy-ass shit? Yeah, he's NOT a god. Nope. NOT A GOD. You got that? Good. the Kami are just fine, all the metaphysics of the next world are clean and pure and unsullied still. it's this schmendrick over here who's got egg on his face, not Ameratsu and the pantheon'. To my perspective, this may well have answered a GREVIOUS amount of doubts that the Japanese people had, and allowed them to pull it together and get their shit running again, rather than floundering around, wondering why the gods were so deeply fallible.