Light Bulbs in Japan

From "The Economist" magazine I learned that Japan has both 50 & 60 Cycle generators. This came about because at the time of installation, some of the parts were bought in the U.S and the rest in Germany. It is also the only place that has 100 volt power, not 110 or 220. Japan has ten electric companies and they don't cooperate which makes it hard for any moderation to be done.