I was in Takayama for the Japan Do on Sunday, and there was a shop selling honey that had DCC. I saw another customer who had a Citi AAdvantage card. She did try to do a contactless payment initially, but it failed. When she inserted, the DCC prompt appeared. The shop employee was ushering the customer to make the currency selection, and the customer did select JPY without any prompting. It looked like the markup was 4.5%. I did a tap payment successfully, which defaulted to JPY without any prompting. There was a Canadian in our group who also did a contactless payment, but he had to enter his PIN for the transaction. I didn't require any signature, and the customer with the DCC prompt had to sign.