I have lived in Japan for 18 years, however there are many customs that I don't know.
Recently I'm interested in Japanese culture, so today I learned it and I will write here.
I learned at first is "present custom".Japanese often give presents to friends,company and even teacher. When you were given something for presents, you have to give a present for return. However you don't have have to buy something that is same price of given present.It's must be half price. I think it's because many Japanese fill sorry when they get something without paying,(except birthday or other cerebrations), so they want to give something for return. However, if people give presents and he get something that looks same price, he will fill sorry for the paying. For these reason Japan has "half return"culture, I think.

