Your best bet is to have a phone with a SIM, that is unlocked. Then, get a prepaid SIM in Japan with a local number.
your best bet in roaming with any country is usually to get a GSM phone.
Not in Japan.
ok so I have a Samsung Mythic and Motorola Razr v2 deactivated from AT&T and a Verizon iPhone.
Is there a better method than the Verizon $1.99/min plan for Japan?
They have an International Roaming Plan with $1.99/min.
Is there any other type of service I can use instead without having to rent another phone?
I have a Samsung Mythic on AT&T too that can be reactivated there if that works.
One of the iPhone's major fail points (GSM/AT&T variant) is that you had to unlock them without Apple or the carrier's approval to use them internationally. The Verizon model reportedly has a radio capable of handling a SIM card/GSM frequencies, but that wasn't included in the physical design of the current generation.
Why not just rent a phone at the airport? DoCoMo usually have stores there to provide for rental. The data rates are generally fairly acceptable
I can see in the future that they will streamline CMDA and GSM versions so they don't need two production lines.