100V Power

Japan is the only major country in the world that uses 100V as its nominal supply voltage. Eastern Japan (Tokyo and east) runs at 50Hz; western Japan (Osaka and west) runs at 60Hz. Frequency-sensitive devices (clocks, motors, some kitchen appliances) may behave differently depending on which side of the country you are in.

For travelers from 120V countries (US, Canada, Mexico): most dual-voltage electronics work directly with only a plug-shape change (Japan uses Type A/B plugs, the same as North America). Single-voltage appliances rated specifically for 120V may run slightly hot or hum because the supply is only 100V — typically harmless for short trips but worth checking the appliance spec plate.

For travelers from 220-240V countries: a step-down converter is required for any single-voltage 220V appliance. Most modern dual-voltage electronics handle 100V natively because the supported range is usually 100-240V.