I dropped in at ampm, a convenience store.
When I was about to buy a piece of fried chicken, I noticed that I didn't have enough small change to pay for the chicken.
So, I asked a clerk at a cash register whether I can use credit cards. He replied "We don't accept any credit card. We're sorry for your inconvenience."
As a result, I had no choice but to pay a 1000yen bill.