Our family lived in Japan for a summer. Of the many surprises was the extensive use of cash. The most shocking thing to me was the mailing of cash for transactions. Even more surprising, people who mailed cash used special envelopes, I suppose so that the postman would be more careful. This would never work in the US, or most places I have been. From the Guardian (UK)

Tokyo citizens hand in record ¥3.99bn of lost cash