[Nyororin]

Cash is still preferred, but Japanese people not using credit cards is SERIOUSLY out of date. People will even use their cards at the convenience stores...

The most common type of "e-wallet" you will see here is the type built into cell phones. It`s usually prepaid, but I think you can set some of them up like debit cards.
That`s really all it is in the end, a debit card. Japan never jumped on to the debit card thing, and never used checks. For some reason people seem to think that e-money is something bigger and more mysterious - but it`s just taking, say, the same niche that checking cards and debit cards take in the US.