Change your SIM card to Japan Travel SIM!
Japan Travel SIM offers a simple and convenient way to stay connected whilst in Japan, and importantly offers great value for money and the avoidance of expensive roaming charges. For a fixed upfront cost, you can get 1.5GB or 3GB of data access for 30 days valid across the whole of Japan, with the option to top up if needs be. Be sure to visit their stand to get your connected Japanese visit sorted!
It is very easy to swap SIM card even though you have never done it before. First take out your SIM and Insert Japan Travel SIM. Follow the manual included in your SIM package for APN settings and user registration, this is a quick and easy process allowing you to use the data and roaming service in Japan.