Bill paying in a cash economy
So, Japan is a cash economy. Credit cards are only really accepted by some institutions in major cities and checks are what businesses write to pay each other. So how does one pay large bills without mailing sums of money? Why, the convenience store! Most monthly bills mailed in Japan have bar codes on them. When you get one, you can take it down to the conbini, where they scan it, stamp it and then return half of it to you as a receipt. It's not neceessarily more convenient (well, it wouldn't be, except we don't have a mailbox), but there's no worry about losing cash in the mail. If the company complains, you have proof you already paid.