[GoNative]

Obviously rural Hokkaido, or probably anywhere rural Japan, is going to be very different to major cities like Osaka and Tokyo. I can only comment from a rural Japan perspective as I've never lived in the big citites.
The credit card comment is based on my experience here that it's very difficult to find many places, including some of the large supermarkets, that accept credit cards (beyond maybe ones they distribute themselves). Before I left Australia it had basically turned into a society where few people carried cash anymore. Pretty much all money transactions could be done by credit or debit cards. All bills could be done by internet banking (I've only just recently managed to get some of our bills here paid by internet banking). People really just didn't carry much cash anymore. Here, as you know, it's hardly unusual to see people walking around with large amounts of cash. Many employers still pay in cash (something practically unheard of in Australia these days). Overall Japan is much more of a cash based society from my experience.