The power supply is 100V/50Hz in Eastern Japan and 100V/60Hz in Western Japan, but most electrical items can be used in both areas.
Electric outlets are identical to 2-pin North American outlets, and many portable electrical devices from the U.S. will work without a problem in Japan; however, using a transformer is recommended. For other countries, a plug adaptor and transformer are necessary. Larger electrical appliances brought from abroad, especially household appliances, will not work in Japan.
