Chrismukkah

Jewish people celebrate their annual festival called Hanukka while Christian people celebrate the birth of Jesus on Christmas.
I first learned the existence of Hanukka when I heard the word "Chrismukka" in The O.C. (a popular sitcom for teens). What a witty expression the "Chrismukkah" is! It's a portmanteau word combined Christmas and Hanukka used among non-religious families mixed Christian & Jewish background. Applying this word, they can celebrate both holidays at once :)

Speaking of the non-religious families, most Japanese people are non-religious. We take Buddhist or sometimes Shinto or Christian way for funeral ceremonies. Other than that, however, most of the families seldom touch a religious talk, and often kids are not aware which religion of background they have.
Nonetheless, we have a custom of celebrating Christmas in Japan. It's weird, but we just decorate a Christmas tree, and eat a big feast with a Christmas cake without thinking about Jesus for even a second. Parents prepare Christmas presents to their children, and couples in love exchange presents each other. But that's it. Unlike most American people, we don't make a Christmas shopping list to buy presents for all the relatives.