Your Options:
During the initial order process, you will be given the option of an 8 Day, 16 Day or a 31 Day version of the ‘Japan Tourist’ SIM card.
Your SIM card will arrive active and the 8, 16 or 31 day service duration will just begin from the day that you first connect to the Docomo network within Japan.
As this is a pre-paid service, you will only be charged for the initial purchase and no further charges can be incurred.