I shouldn't even say if because it's happening now. The yen's fallen more than 20% in the past 6 months. Their government is printing 7 TRILLION yen every month for two years to force inflation. That's almost as much as the Fed is doing in an economy that's a third our size. I'd put my money in US stocks. I tend to think Buffet's right about gold being a lousy investment and really don't have any idea how bitcoins will do.
It's not if you're Japanese and it causes a bond crisis. Their debt equals over 20 times their government's revenues. Even 2% inflation will cause yields to move and debt service to exceed government revenues. They will be forced to default or inflate. Either will cause the value of the yen to nosedive.