Ensure you have the right plug type, understand the differences in voltage and frequencies before arriving in Japan. Japan voltage is 100 volts Alternating Current (A.C.). North America typically uses 120v and Central Europe uses 230v. Incredibly though the country operates on two distinct frequencies—50 Hertz in the east and 60 Hertz in the west (you may recall it was incredibly difficult for Japan to supply power from western Japan to eastern Japan after the Mar 11, 2011 earthquake).
To the right, you can see a typical Japanese plug type. It is quite rare to have an earth prong although from 2015 new construction standards require it. If there is a ground consent, it is normally for fridges, washing machines, etc. It is normally a third cable rather than a third prong. It is the same as North American plugs except there is no earth prong.
You can buy transformers and plug convertors at most home appliance retailers like Yodobashi Camera and Bic Camera.
Recently, many convenience stores offer eat in areas in their stores. You can often find an outlet there, too. If you take the Shinkansen, you can normally find an outlet in newer trains.
