I was aware that SCAP (MacArthur's office) wrote their constitution for them, and I do recall them stripping the Emperor of his divinity - knowing about the temples being disestablished comes from a brief study of Japanese religion. OTOH, they have a more parliamentary form of government than we do, fundamentally modeled on the German Second Reich and not changed all that much (if at all) by the new constitution, but I could be wrong about that.