The voltage standard and plug shape will differ from country to country, so there is no guarantee that an electrical appliance bought in Japan will work in another country. That will be also written in the product manual. In many cases, this explanation will be posted in the display area where the product is sold. It might be best for a store employee to explain this clearly as well, but just because you did not get a verbal explanation is not a good enough reason to be able to return or exchange the item. You can try, though. Go back to the store where you bought the item and ask if they might be willing to exchange the item for a similar one they sell that will work in your country.