
Here is an actual photo of a Japanese power outlet
Japan is one of the only countries outside the Western Hemisphere to use Type A and B outlets, the same as in the US. Type A sockets are ungrounded and have two flat holes, while Type B sockets are grounded and have a third hole. Unlike in the US, the ungrounded, two-flat-pronged outlet type (pictured) is most common in Japan.
The electrical grid in Japan has two other oddities. Most countries use the same frequency everywhere, but that’s not the case in Japan.
In the eastern part of the country, including Tokyo, the frequency is 50 Hz; in the Western part, including Osaka and Kyoto, it’s 60 Hz. The difference in frequency generally isn’t an issue, but it can prevent clocks and timers from keeping time correctly.
The voltage used in almost every country is either 120V (in North America) or 230V (in most other countries); however, Japan uses a voltage of 100V, the lowest in the world.
Even though the electrical grid in the US uses a voltage of 110V, many American appliances are rated for a range of 100-120V.