If I am in a perverse mood, I will pay for my morning coffee + danish in trouble-making fashion. Breakfast comes to 601 JPY, and sometimes I will give the person at the counter 802 JPY. There is never any complaint. They take my money, put it into the register and give me my 201 JPY in change.
Similarly, although not deliberately this time, I forgot to pay the sewerage component of my water bill (which was 376 JPY). The water people sent a guy round to collect it from me in person, and initially I didn't let him in because I thought he might be from NHK. He was extremely polite and bowed after I'd paid him in small change.
The feeling of being Japan is never quite knowing how much of an ....... people really think you are.