It is common to give Christmas presents in Japan, and Santa Claus has even been imported to take part in the holidays. Within the family, parents give presents to their children, but the children do not give presents to the parents. The reason for this is that only Santa brings presents, so once the children no longer believe in Santa, the presents are no longer given.
There is also a joke that compares Christmas to a woman's age. Cake shops throughout Japan always try to sell all their Christmas cakes before Christmas Eve. Any cakes left after Christmas are seen to be very old or out of date. Unmarried women over 25 years old used to be called 'unsold Christmas Cake.'