content: The serious, actual answer to your thought is due to how their society is structured. Japan's culture has always been very formal and serious in many ways, and duty takes a high priority. When you throw overpopulation and the psychologically disastrous modern era of business and life into the mix, you suddenly have tons of people who are being exposed to massive amounts of pressure and stress. More than a human mind is really meant to take on a daily basis. It's why the suicide rate there is so high. The wacky stuff in Japan is partly their cultural way of venting the frustrations of having such an "oppressive" cultural atmosphere, and I'm using oppressive here to mean the same kind of thing you'd describe if you walked into a loud, dark, stuffy club. When you pack lots of humans together and throw tons of rules and pressures and stresses on them, you're going to see fracture lines somewhere.