Germany only worked because of 45 years of formal occupation. It didn't take my compatriots long to return to an auhtority-craving society with a democracy as defined by Karl Marx and Friedrich Engels, the major parties having formed an informal socialist bloc and the serious opposition being denounced as far-right. That's one of the reasons I moved to neighbouring Czechia several years ago.
In Japan the emperor stil exists, though he has no power beyond ceremony anymore.