Electricity

The voltage here is 100V therefore not bring electronic devices 220V.

If you bring an appliance will need to buy an adapter.

In almost any electronics store in Tokyo you can buy an adapter.

Drinking water

Tap water is drinkable in addition to having good taste. If you want another drink will not have trouble finding it, there are vending machines all over city and convinience store open 24 hours a day.