Why don't Japanese people celebrate Christmas?

Answer 1

Christmas is a Christian religious celebration. Very few Japanese follow Christianity, most follow religions called Buddhism or Shintoism.

Some modern Japanese may be inclined to celebrate christmas by giving gifts, but not observing any religious aspects

Answer 2

Christmas isn't a national holiday; it is celebrated internationally by mainly Christians for religious reasons. Many people (both Christian and non-) celebrate Christmas, though non-Christians celebrate it only as an event for gift-exchange or parties. This said, most Japanese people do celebrate Christmas both for religious practice and simply eventful partying.

Answer 3

Christmas is a Christian holiday so Christians in Japan would celebrate Christmas.