Hi. I’ve just returned from Japan and have a few things to add.
7-11 (7Bank) and JP Post have both started charging for ATM transactions. Withdrawing 20,000JPY had a 216JPY fee at a JP Post machine, not sure about 7Bank. They used to be free, so it’s something to be aware of.
International chip+PIN card acceptance seems to be growing around Tokyo, but it’s still advisable to carry a fair amount of cash, particularly out of the major cities.