If we're talking about the Sapphire cards, get that upgraded to a chip card as soon as you can. The magstripe does have issues with certain stores- that's when I use my Bluebird, which as far as I can tell, has worked at every shop that tells me they do a region check.

Yep, that's why my Chinese debit card is my go-to card for cash when in Japan. If they take cards it goes on a card, if they only take cash it's nice to not be as limited as others, since Aeon, Mizuho, and Mitsubishi-UFJ combined have enough of a presence that I never have to worry about finding an ATM until late night (why do they shut down their ATMs at night ).