When you do find a store that takes credit cards (usually the larger, chain stores in malls) and you buy something, the clerk always asks "One or two?" (Actually, they usually just hold up one finger, pause, and then two fingers.) This was tricky at first. No amount of gesturing can convey what they're really trying to ask: they will split the payment for you over two months if you prefer, so they are asking, would you like this billed to your credit card in one payment or two? I've always used the option of paying for it in one billing, but I should find out if there are fees for the other option. My guess is that there is not; it's probably just a convenience thing, or as the Japanese would say, "For service."
I try to use cash even when a store accepts credit cards because of a little incident that happened about a month after I moved here that still bugs the crap out of me. I purchased some curtains for my apartment at a local store called Nafco. There aren't enough giga-whatevers in the world to describe that experience, but let's say it was time consuming and frustrating, and I wanted to swim back to the US immediately afterwards. Summary: after three visits and about five hours, I purchased some curtains with my credit card and took them home to my little shoebox apartment. They ended up being the wrong size curtains, and I had to return them. Even typing that word makes me shudder. I've repressed most of the event, but I do remember that it involved the non-English speaking clerk calling Citibank, the credit card company, in NY, to ask permission to refund the cost to my account. Citibank, of course, didn't know what the hell they were talking about, and I didn't either. But the store couldn't do it until they had permission (über-Japanese concept; let's all follow the rules, shall we?) Anyway, long story longer, I think I got the curtains returned, but I have a bunch of other crap that I bought on my credit card around that time that I didn't need but that I refused to take back. It's just too traumatic.
And now I use cash.