I have a US Wii which I am using in Japan. All of the controllers bought in Japan work fine with the US Wii however I tried to use a friends balance board and it didn't seem to want to sync up. The power button just kept flashing for a few seconds and stopped. I was under the impression that accessories for Wii would work on any Wii and only games were region locked. Can anyone throw any ideas at me? Cheers Niallerc **** found the answer myself very simple I fogot to use the sync button located in the battery case... duuuhhhhh**** So the answer to the question is yes the Jap balnce board will work on a US Wii.