The Willer Bus Pass is considerably cheaper than the Japan Rail Pass, especially if you travel on overnight buses to save on hotel/hostel costs. It’s best if you are want to mainly check out the big cities or tourist destinations, as the bus routes only go to these kind of places. You can buy a pass online at Willer Express. Once you have the pass, you need to reserve the seats for each bus. This can be done at the Willer Express website or at one of their bus terminals. Just show the driver when you get on the bus along with the Tourist Visa stamp in your passport.

For the full rules of usage as well as the price list for weekday and weekend travel, head over to Super Cheap Japan and get the details before you go.