Japan uses a version of the NEMA 15amp outlet, but it's not quite the same.
The two pins are of equal size, non polarised and there are slightly different spec.
Most Japanese outlets are not grounded, so appliances like Washing Machines and cooking equipment has a seperate ground lead that is connected to a bonding post on the end of the outlet.
They also use 100V 50Hz/60Hz.. not 110-120V 60Hz as in north america.
