Japan doesn't have a lot of free WiFi. It's true.
No matter what you've heard about Japan and electronics (which are amazing-heated toilets and airplane windows that darken when you push a button, touch screens to order almost anything at an izakaya, bullet trains...) WiFi isn't readily available for free. Before you go, definitely check that your hotel offers free WiFi, and make sure you're set for tethering your devices and have a portable router. It's worth it, we promise.