Originally Posted by YariGuy

If you think the rate will continue to drop (meaning US dollar getting stronger) then you can just wait until you get to Japan, and use your ATM card to withdraw cash (or just use your US credit card). If you want to lock in today's rate, then the best I can think of is to charge up your Suica. But I don't know what the cap is on that, or whether you can get multiple transportation type cards (交通系ICカード) on your phone. I would think you can - Suica and Pasmo are just 2 that come to mind. I find that these payment types are becoming more and more widely accepted so it's like a partial hedge.