But the Japanese do not fully acknowledge what they did in the war and a lot of the history is not taught to the young. This contrasts with Germany which basically acknowledged what was done and set about purging it from society.
The end result is the same. Germany had a fanatical idealogy focused on Hitler, ethnic purity and the Fatherland. When he was out of the picture and the country clearly was never going to win, it became relatively easy to convince everyone to throw out all the old flags and make that idealogy a crime. Ethnic purity is just not acceptable. They needed to shove that all under the rug.
Japan had a fanatical idealogy focused on honor, empire-building, and the Emperor. The Emperor lost his divine power and the US planted a democratic constitution and government, and prohibited Japan from having an offensive military. But today, they still have the Emperor, a code of honor which is nonviolent now but still around, and they still build their empire in the Pacific and elsewhere (economically). They don't need to make their old ideology a crime because they can still achieve it in different, internationally-acceptable, ways. They didn't need to purge their idealogy completely because once nonviolent boundaries were attached, it wasn't a problem anymore.