Try K Bank, take your wife with you. Blue Housebook if she owns house, or rental agreement, your passport her ID and some cash as deposit. I did this with my GF , now wife, on a 30 day tourist visa. Just keep trying different Banks if you dont succeed first time around. Good Luck.
Stuart, James is correct, go to a K Bank, with your girl friend, her ID and your Passport, and your cash of course. Open a Savings Account (Easiest) and they will give you an ATM card.