In Japan, cash still rules over plastic money - or at least over internationally issued credit cards. Most shops and restaurants do not accept foreign plastic money (I haven't really checked whether they accept Japanese cards, but I haven't seen anyone pay with a card so far). Ticket machines and other vending machines operate with cash only.
Even when it comes to ATMs, not all of them are created equal. Most ATMs do not accept international credit cards. Only those owned by two or three certain banks are connected to the international network. Luckily, the fairly common Japan Post ATMs belong in this category.
I'm even supposed to pay the rent for my apartment in cash. What a strange notion, to carry a wad of cash to the landlord every month.
So, I guess I should feel lucky that I received a part of the allowance for my scholarship in cash today. I believe I've never had such a large amount of cash with me. And without a bank account (I haven't opened one yet) to put it into - where am I going to keep it? Under my pillow?