In Hokkaido, you can find a lot of ATMs with PLUS (DBS) or Cirrus (Posbank) that you can withdraw money.
In Fukuoka, the only bank so far is JP Bank ATMs, and it is usually beside a post office. The rest of the bank ATM are very unfriendly. Strange, Fukuoka suppose to be 3rd largest city in Japan.
and DBS/POSB will charge $5 extra for each withdraw.