I think this is an excellent choice, very useful when you are traveling around Japan, and you need to always carry devices that connects to Internet. This is Mobile router with High Speed download/upstream capabilities. And the service is really affordable. The downside is however the cap limit to navigate, 2GB for a two weeks plan, and 4GB for 1 month plan. I understand that when the cap is over, the carrier will throttle the connection from 100MB to 128KB, is not actually a limitation from RTM but rather from the carrier. So is fair to say that this is only useful when using tablets and smartphones.