Tap water in Japan
It is quite clean and safe; it is drinkable.
You can also easily buy some PET bottled water at local vending machines or convenience stores. It costs about 100 yen-160 yen for 500ml.
The voltage used throughout Japan is uniformly 100 volts, A.C. A step-up transformer is required to convert the voltage if your hair dryer, travel iron, etc. are not a convertible type.
2-flat-pin plugs (Type A) is used. You will need a plug adapter if you are using a different type of plug in your country.
Frequency of electric current
There are two kinds of frequencies in use; 50 Hertz in eastern Japan and 60 Hertz in western Japan (including Nagoya, Kyoto and Osaka).