Comment by tionate
Old school but all the machines for paying in cash in Japan are so optimized for speed. Train stations, onboard buses, convenience stores. Just throw in a handful of coins and it quickly picks what it needs and returns what it doesn’t.
In other countries (eg australia), the ticket machines could only take a single coin at a time and would reject if you did it too fast.
I believe this is one (of several) reasons why cash has continued to be dominant in Japan.
Sydney lets you use your credit card to tap on to trains and buses, which is very nice