what do they eat in japan for christmas

They don't really have a traditional Christmas meal in Japan. The most popular dish is KFC, but that's a recent trend started by the fast food chain. The traditional Christmas dishes in Japan are roast chicken, Christmas cake (which is usually a sponge cake covered in whipped cream and strawberries), and Japanese Christmas pudding (which is a steamed pudding made with fruit and nuts). The traditional Japanese Christmas drink is orenji soda (orange soda).