Data communication only service
Use of voice communication is not possible.
(*Telephone calls with SNS apps are possible)
SMS only supports receiving messages.
4G (LTE) high-speed internet
You can use high-speed internet with maximum download speeds of 788 Mbps and maximum upload speeds of 50 Mbps.
The available area is all throughout Japan
Available all over Japan. See here
for further details (Japanese page)
APN settings are unnecessary
You can use it easily without APN settings, by just inserting the SIM you receive into your smartphone.