Decemberis busiest month of the year. It is called Shiwasu which means even Buddhist monks are running. People will be busy for great cleaning called "Osoji" before New Year begins. Also, they have to write Negajo letters. Some people write several hundreds Nengajo letters every year.

December is the first month of Japanese winter, so there is few rain, and air getting so clear. Even from Tokyo, Mt. Fuji is clearly visible. It is very cold, but the weather is mostly sunny, so nice time to travel.

In the Christmas time, many cities will have great Christmas light up show. New Year's Eve is called "Omisoka." People start visiting shrine and temple at night just before the mid-night. This new year's worship is called "Ninenmairi" which means having worship for over years.