It's still feasible that there are Wii shortage in Japan if Nintendo is putting more effort into the US and European markets. Whatever the situation in Japan is by all accounts they're worse in the US and Europe. Shortages everywhere, and I don't think it will be solved for at least a few more months. In Japan you might have a shot to find a Wii, in the other two if you're not at exactly the right place at the right time you're out of luck.