On a recommendation from a friend, I purchased a 7-day plan for a 4-day/3-night trip to Taiwan. After purchasing the plan, I tried to set it up at the airport before boarding the plane, but was unable to do so successfully. After arriving at the destination, they checked to see if the data roaming was working properly, and when I inquired whether the data roaming was properly restored for domestic use after returning to Japan, they immediately responded to my inquiry. I have been using a carrier's global data communication service, but this service is cheaper than that, and I would like to use it again in the future.