Imagine someone saying “Merry Christmas” with a really strong Korean accent – welcome to South Korea:D Most of the time it’s below zero and sometimes we have a white Christmas, except in the southern part.
Since 30% of the people here are Christians, those are tho ones who celebrate Christmas traditional. Still Christmas day is a holiday for the others as well, for example for young couples it is usually regarded as a special-date-day. In this case it’s very commercialised and you’d need to buy presents for your girlfriend. When having a family, the children get some gifts to open them on Christmas Eve.
Foodwise there is nothing traditional because Christmas in Asia is not long established yet. That’s also the reason why Santa Claus is not more than a commercially used figure for the Christmas time. At least it’s kind of popular to eat cake when celebrating with your family.
Some people might also decorate their living room with an artificial Christmas tree. Furthermore the movie Home Alone is broadcasted every year during Christmas.