+1. No problem using Chase cards (with chip + sig) anywhere in Tokyo and we charge everything we can including 7/11 and Starbucks (need those miles!). However as others have noted credit cards are not accepted everywhere, notably: metro machines and most tourist sights are cash only and some of the cheaper restaurants (though happy to pay cash there given the savings) )

We had no difficulty using Chase ATM and Fidelity debit cards at 7/11 ATMs which are easy to find in Tokyo - there are even some standalone 7/11 ATMs in metro stations (though I didn't use those as I am neurotic about skimmers). Also used Citi ATM card to get cash at Citibank (though not preferred method due to 3% forex)

We are burning through about $100 cash per day which is high for us and an indication of how many places do not accept cash.