Apparently Japan was first electrified by the British, who use 50Hz.
Then the US bombed the country (something about a little picadillo called WW2).
When the US rebuilt the destroyed parts of the electric system after the war they used the 60Hz US standard frequency.
Thus arose the unique situation that if your job transfers you from one end of the country to the other you may not be able to take all of your appliances with you to your new home.
I remember reading a story about Siemens (50 Hz) and GE (60 Hz), well before the war. That seems more likely to me! I also believe that most Japanese equipment is dual-frequency rated for that very reason. Make sure that all transformers and motors have enough iron to run on 50 Hz and if running speed of something with a motor is critical make it a belt drive with two pulleys or use a DC motor.
