I would spend some time there first before making such a huge commitment. Materialistically Japan or China are even more so when it comes to the big cities. That's not to say all of Japan is like this. I found Yufuin to be beautiful and would probably be to your liking. It was a small country area and many of the people I had met there were from the bigger cities who had wanted a more quiet and peaceful existence so they had settled there. The lake in town is geothermal so the valley is blanketed in a mist in the morning.
As others have said Japan is more respectful and well mannered than China in general, but best would be to visit them first.
WWOOF - World Wide Opportunities on Organic Farms <---is a good way to experience Japan or China for an extended period.