Keeping in mind Nagoya is a city that is about the size of Chicago and I live right in the center of the city... A couple of nights ago I walked over to a Japanese fast food place that serves cooked meats and vegetables over rice called gyudon or butadon. The restaurant name is Sukiya.
Sukiya's food is really good and really affordable, each plate is about $4. The restaurant is a room that has a counter that jet's out into the center of the restaurant from the kitchen. This evening only one person was working and he was busy in the kitchen and collecting cash as people left. As I was eating I looked up from where I was sitting at the counter and noticed one of the cash registers was in a state of being turned off and some accounting stuff going on. I also noticed the tray of coins next to the register, the coins along the right of the tray are $5 each (500 yen).
I thought leaving money on the counter was a once-and-a-while thing, but I visited Sukiya again for lunch and their it was, more unattended cash-money on the counter. Mid-day though, it was a lot less, mostly 50 yen coins and maybe three 500 yen coins.