A lot of foreign festivals – mostly American holidays – have become part of the Japanese culture. The Japanese enjoy celebrating these events, especially the younger families in the bigger cities. Almost all shops, from big department stores to the popular 100-yen shops, carry Christmas trees on Christmas and Halloween candy on Halloween. I found it very odd in the beginning, as I knew these holidays held no meaning, religious or otherwise.
A lot of older Japanese people like to tell this bad joke about being multi-religious: They are Shinto on New Year, Buddhist on Obon and Christian on Christmas. I’ve never found this joke funny, but I understand what they mean. My Japanese friends like to tell me that they, as a people, like to absorb Western ideas and culture, and then try to make it adaptable to Japanese standards or circumstances. Automobiles, robots, electronics, modern medicine, fashion and (now) festivals are just a few of the things which Japan has imported from the West, but have made their own.
One of the reasons these festivals have become so popular here is because of Tokyo Disney Resort (where Tokyo Disneyland and Tokyo Disneysea are). Tokyo Disney Resort goes all out for the holidays. Both parks, the surrounding hotels and even the station are festively decorated. It is probably the best place to celebrate Christmas and/or Halloween in Japan. I’m thinking of heading over there again soon so I’ll have an excuse to wear the Christmas Minnie earmuffs I bought two years ago and never really wore again…
According to Japan Probe, the Christmas season has started at Disneyland.
Updated (November 15,2007): See how popular Halloween has become here. Check out this video about the Kawasaki Halloween Parade (I think this is from 2006):