Of course, there's also a surcharge if you use a machine that does not belong to your bank. There are some ATMs in Japan which accept American ATM cards, but they are also scarce and tend to be in touristy areas. Japanese banks are notoriously slow. Use ATM machines as much as possible. Japanese really do take off their shoes in their home and expect foreigners in Tokyo to do likewise.
Slippers are necessary at many temples, shrines and castles.
Slippers big enough for western feet are hard to find in Tokyo. If you are there during winter, consider really warm slippers. Temples, shrines and castles are generally unheated. Japanese are very big on gift-giving. If you are someone's guest, they may give you a gift as well.