This my "rabbit's foot" joke that I play every time I come to Japan. I go to the convenience store at the airport and buy something, then earnestly hand the unsuspecting clerk a Canadian $5 bill.
If, after saying "Just kidding," (冗談) they laugh, it is going to be a bad trip. If they don't laugh, it's going to be a great trip. This woman practically punched me in the face (because of the camera, no doubt.)
It's going to be a great trip! Three out of five, anyone?