It is a ceremony to honor our ancestors and to come together to chant the nembutsu. At this time, families visit their family graves and also gather at the temple for a communal ceremony. This is a Jodo Shu tradition of followers gathering together to chant the nembutsu through the nights of ten days. Nowadays, it usually lasts for only a few days. Komyou-ji in Kamakura, one of the seven main temples of Jodo Shu, has been holding Ojuya frequently and now, many Jodo Shu temples in Japan do the same thing.
Follower then can welcome the new year with their fresh and holy themselves.
The night of December 31, the last day of a year, is called joya. The original meaning of joya in Japanese is to stay awake throughout the night. On December 31 at midnight, temples of all over Japan ring their bells to welcome in the New Year. The temple bell is rung 108 times, symbolizing the washing away of the 108 human defilements and the beginning of a purified new year.