Japan is hugely a cash-based society, and it's a good idea to take out as much money as you think you'll need for your trip. However, if you are ever strapped for cash, there are a few places to go to make international withdrawals.
1. You can withdraw money from any ATM at any JP post offices. The ATMs have an English option and there is no withdrawal minimum. (7:00-21:00 Monday to Friday, 9:00-17:00 Saturday, Sunday, bank holidays)
2. You can withdraw money from any ATM at "Seven-Eleven" 24HR convenience stores. The ATMs have an English option and there is a withdrawal minimum of $100. hav
3. You can withdraw money and exchange money at any Travelex. Here is the list of Travelex
locations within Tokyo (Kanto Region).
Keep in mind that not all cards are compatible with all of these machines. It's also a good idea to notify your home bank that you will be traveling overseas to avoid any withdrawal problems.