If you have purchased a physical Data-Only SIM Card, we can confirm that the SIM card is already active / ready for use and so you will not be required to submit an activation request.
The 8, 16 or 31 day plan will simply begin from the day that you first connect to the network within Japan.
Maintenance Window:
Sometimes, between the hours of 10pm on Tuesday to 9am on Wednesday (Japan Time), the network will undergo system maintenance.
This could mean that if you try to use your SIM card for the first time during this period, you may not be able to connect. Also, you may not be able to connect to the network immediately after maintenance due to congestion. If that’s the case, we’d suggest waiting a short time before attempting to connect to the network again.
If there are any issues accessing cellular data after arriving in Japan and connecting to the network however, please ensure that your device has been configured with the correct APN (Access Point Name) profile settings as shown in the relevant guide below –