The Yen Dropped

We were on an expedition to buy a toaster. The shelves sagged with all sorts of toaster-like objects but no prices were visible on any of the items we sought to know more about.
Spouse turned to a customer standing nearby and considered for a long while the appropriate next move. The fellow, a Japanese man, was involved in a similar struggle to locate those wayward prices and was, one would reasonably presume, as much in need of toast as I.
"Do you know the price of this one?" Spouse asked in Japanese as if nothing were out of the ordinary.
The fellow began to reply quite honestly, in Japanese, that he did not; but in an instant the yen dropped. His expression underwent a significant transformation; he took a step backwards, displaying all his teeth in perfect shock.
"But how?" he gasped in Japanese. He was thoroughly and genuinely astounded.
They talked for a few minutes. The Japanese man shook his head repeatedly. But he was very happy all the same for the strange encounter.
Spouse chuckled to himself during the journey home. He had internally debated whether to speak up and indicate that he spoke Japanese, but thought to proceed with caution in case the customer should be startled out of his wits.
Mercifully it turned out well; the fellow, dazzled, glided away to tell the tale to his wife and children in the next aisle.