Few apple stores in Japan

My NIKE+ system has not been working for around a year.
I thought it was due to battery ehaustion, but buying a new battery did not work out.
So, I think it's due to some problem of the wireless receiver, or of the interface between iPod nano & the receiver. I still want to measure battery voltage, but I can't because the battery is packed for water proof.

I went to a sport shop, but they were not able to help me. They said that they're just selling them.
Then I thought it seems better to go to an apple store.
So I checked the website, and was surprised that only 9 countries have the stores, and there're only 7 stores in Japan, although it is not bad that the closest one is at Shinsaibasi which is not very far from NAIST.