Cheap fast wireless for travel to Japan

I spent almost five weeks in Japan this summer. My T-Mobile plan includes international data but it is pretty slow so I rented a Pocket WiFi from eConnect. I ordered it in advance and picked it up at the post office at Narita Airport. I bought the 50GB plan for about $125. When I came close to running out (our traveling party of five used it pretty much non-stop on their phones and laptops) I bought more data for about $1 per GB. It was very fast and worked everywhere we went, including the remote mountain town of Koya-san. At the airport on the way home I put it in the return mailer and dropped it off at the post office. — MF