MONEY, CASH, CARDS, ATMs
Japanese businesses increasingly accept credit cards. There are still a few cash-only restaurants. In rural areas, some small family-run hotels and hostels may also be cash-only.
How much money should you carry? How easy is it to find an ATM which will accept your foreign-issued card?
http://www.flyertalk.com/forum/showthread.php?t=492796
ATMs at 7-Eleven (7 and i) convenience stores accept many foreign issued cards. The same is true of ATM's at Lawson convenience stores, but not ATM's at some Family Mart stores:
http://www.flyertalk.com/forum/showthread.php?t=693884
Make sure that your cash card has a "CIRRUS" or "PLUS" logo on the back. If it does, then it should work fine at ATMs in Post Offices and Seven Eleven stores. Unfortunately, foreign cards will not work in many banks' ATMs.