For Travel SIM cards (both 3GB/day data SIM and Unlimited data), you will not be able to check the usage since they are unlimited SIM cards for travel use.

NOTE ABOUT THE 3GB/day data SIM:

※To manage network resources, the 3GB/day data SIM is managed by a Fair Usage Policy (FUP). This means you won't be disconnected, however, your speed will be limited to 1Mbps after using 3 GB of data per day.

We do our best to provide our customers with large amounts of data that they can comfortably use while in Japan. However, depending on the carrier’s decision, the overuse of mobile communication will affect the usage of other customers and may be deemed as irregular usage. 

※The 3GB/day data SIM Card does not support long-term video streaming, video-conferencing/calling for extended periods of time, or downloading large amounts of data. 

If you plan on using the SIM card for such purposes, please select the Unlimited data SIM card instead: https://www.sakuramobile.jp/travel/sim/