‘Laugh at one yen, cry for one yen’ is a Japanese proverb to urge frugality.
I always feel uncomfortable about rounding when shopping in New Zealand. I once protested when a greengrocer tried to charge me $3 for something advertised for $2.99, even though I was using my bank card. One yen is very important for me, and I think for many Japanese too. All the shops and supermarkets give you one yen coins for change, without any mistake. A café in Japan went down quickly after they tried to round.
Have you ever wondered why Japanese currency has only yen, not like dollar and cent or pound and pence? (We actually don’t call Japanese currency ‘yen’. It is pronounced ‘en’.)
We had ‘sen’ just like cent or pence. In 1953 sen coins were abolished most likely due to the hyperinflation after the war, but the term still remains in the share market.
$2 shop is ¥100 shop in Japan, and they have charged ¥105 and now ¥108 according to the different percent of GST. Of course they give you 2 yen for change.