There is a lot of confusion surrounding the use of overseas mobile phones in Japan. Please note that the information given here is intended as a guide only. We cannot be responsible for charges made by operators or rental companies. You will find that charges for using a mobile phone in Japan are expensive and this is especially the case for data (email and internet) - we recommend you turn off roaming on your mobile telephone to avoid a nasty surprise!
One great option is to hire a mobile phone in Japan. Please see the next FAQ.
The mobile phone network in Japan works on a different system to the rest of the world and until recently no overseas mobile phones would work. However, with the advent of 3G phones this has changed. The rule is basically this: If you have a 3G handset, it will work. If you do not have a 3G handset, it will not.
Be careful: If you ask your mobile provider they may inform you that your phone will work in Japan if it is tri-band or quad-band. It will not.
BLACKBERRY: If you have a 3G Blackberry it WILL work in Japan. If it is not 3G it will NOT work in Japan.
Please note: some mobile phone contracts do NOT INCLUDE ROAMING. if your contract does not include roaming YOU WILL NOT BE ABLE TO USE IT IN JAPAN.
Another option is to hire a SIM card in Japan and put this into your own mobile phone which you have brought with you from home. Two companies offer this service: Softbank and Mobal Narita (only available at Tokyo Narita Airport). As of September 2010, Softbank is much cheaper for domestic calls within Japan (105 yen per minute). Calls to the US are 200 yen per minute and to the UK 250 yen. The Mobal Narita service is 240 yen for domestic and international calls. SMS (text) messages on Mobal Narita are 140 yen each whilst on Softbank they cost 150 yen. Data charges (internet and e-mail) for both are very high.
Note that the SIM has to be returned and is not pre-pay. You will need to provide credit card details and will then be billed for usage. Your phone will need to be "unlocked" in order to be able to use the SIM card.
http://www.mobalnarita.com/
http://www.softbank-rental.jp/en/phones/sim3g.php