Christmas in Japan is quite different from the Chrismas celebrated in most countries in which the population has a large percentage of Christians or a Christian heritage. Only 1/2 of 1% of the Japanese population is estimated to be Christian, with the majority of Japanese being tolerant of all faiths: Buddhism, Christianity, Shinto, etc. In spite of this, the Japanese are great lovers of festivals and celebrations, including Christmas.
In Japan, Christmas in known as more of a time to spread happiness rather than a religious celebration. Christmas eve is often celebrated more than Christmas Day. Christmas eve is thought of as a romantic day, in which couples spend together and exchange presents. In many ways it resembles Valentine's Day celebrations in the UK and the USA. Young couples like to go for walks to look at the Christmas lights and have a romantic meal in a restaurant - booking a table on Christmas Eve can be very difficult as it's so popular!
Fried chicken is often eaten on Christmas day. It is the busiest time of year for restaurants such as KFC and people can place orders at their local fast food restaurant in advance!
In Japanese Happy/Merry Christmas is 'Meri Kurisumasu'. And it's written in the two Japanese scripts like this; Hiragana: めりーくりすます; Katakana: メリークリスマス. Happy/Merry Christmas in lots more languages.
Parties are often held for children, with games and dancing. Japanese Christmas Cake is a sponge cake decorated with trees, flowers and a figure of Santa Claus.
In Japan Santa is known as サンタさん、サンタクロース santa-san (Mr Santa). Another Japanese gift bringer is Hoteiosho, a Japanese god of good fortune from Buddhism and not really related to Christmas.
But, even, schools and buisnesses are normally opened in the 25th of December, since Christmas isn't a national holiday in Japan.