The local mobile phone operators in Japan use technology that is not always compatible with international networks.

The technical details are way too complicated , but the important thing is to know is that you can't be sure your phone will work as usual.

This also depends on your local telephone carrier and the style and type of your phone.

But if  you want to be on the safe side when you travel to Tokyo, the best thing to do is to rent a phone.

Renting a Japanese cell phone while in Tokyo is usually best.

Renting is a very simple procedure, and the wages are very affordable.

This is really a very simple procedure that you can do at Narita Airport.

There are many companies which have kiosks at the airports.

Other companies will mail a phone to your Tokyo hotel. You can return the phones at the airport or through the mail.