The attitude to all things carnal in the East and West has always been massively different. To give an example, European monarchs did not wash at all at one point, while Asia has never known this disregard for hygiene.
The culprit here is the Bible, which insists that we should neglect our bodies and care only for the souls. In Asia, the body was considered as sacred as the soul. Thanks to the East, we now have massage and more.
Those times are long gone, but in the Western culture there remain traces of human nature being forbidden. In Japan, however, this topic is not a taboo. That’s the third reason why the Japanese seem so different to us.