Maybe too late, but one other advice that I have (that I haven't seen above) is if you're unsure of carrying large
amounts of yen, then you can actually get traveller checks in yen, that way you know exactly how much
you're getting. And they're also slightly easier to cash.
One other financial advice is that many "Combi" stores like 7-11 (7-i) and post offices have ATMs.
That's not too important at TDR, but can be if you go to other places.