Not sure how much cash the kid needs -- yes, both Japan and Korea are still very much cash-based, but even for three weeks, you're probably not looking at much more than $500 if he uses his credit cards wherever possible. Unlike the US, it's possible to find currency exchange places with very fair rates (in fact, in March, I received a better rate in Osaka for exchanging €100 notes than using a "no fee" Visa card), so I'm not sure if it's worth the hassle of opening a Schwab account just for this trip. Probably depends on what the kid is used to and how much inconvenience you want to saddle the guardian with. When I was 17 (in the 1990s), I loved exchanging cash, carrying travelers checks, eurocheques, obscure European savings booklet schemes that woud allow one to withdraw local currency at post offices abroad, etc. Today I guess it would depend on the 17-year-old whether they'd consider that enriching or scary; an ATM card is likely a more straightforward option, although foreign cards don't work at all ATMs in Japan (but it's easy enough to find 7/11 and other convenience stores which have international ATMs) and the ones in Korea can be hella wonky.