Australian mobile phone

Our 14 year old is going to Japan soon as an exchange student. From the research I have done I have found because they are a minor they are unable to rent a Japanese mobile or sim card. What are the requirements for using a Australian bought phone in Japan ? I have read it has to be on a contract (non prepaid) ,have international roaming already on before he leaves Australia and be 3G WCDMA. What other specifications must the phone have ? I don't want my child to get to Japan and find that they are unable to use their mobile phone.

Thanks,
Juliet

I think it(Australian bought mobile phone can be use in Japan) just depends on whether the carrier(your contract of mobile phone in Ausie) is serving roaming service between Japan and Australia.
Japan has been 3G WCDMA ready by 2 carriers, NTT-docomo and Softbank-mobile.
Check the roaming service of your carrier serves.

That's all the criteria. The reason it can't be a prepaid service is that no carrier in Australia has a prepaid roaming agreement with Japan, so prepaid SIMs just won't work there.

As long as the international roaming is activated on the SIM card and the SIM is in a phone that can operate on the WCDMA 2100MHz band he should be fine.

If you're unsure about whether your phone is suitable or whether International Roaming is active on your SIM your best bet is to speak to your phone carrier.