In 2018, I got an occasion to visit Dondo-yaki festival at small village in Yamanashi prefecture.
There are series of New Year's rites and ceremonies out there. The last ceremony is New Year's bonfire that people burn New Year's decorations and old amulets.
The ceremony is called in several ways according to geography. There, it is called as dondon-yaki.
This ceremony is related to the deity called dōso-jin, deity of the ground. You see the flag at the entrance of the ritual place.
It is held on January 15th in the solar calendar or sometimes the date changes according to the lunar calendar.
A day before the ceremony, men prepare several bonfires. Generally, it's women who prepare rice flour dumplings as the offering. Rice cakes are picked to the branch. (Particular tree but I forgot what it was.) It is first dedicated to the altar of house, at my home, it was my grandfather who attaches the branches to the post for the guardian deity of the clan.
The ceremony is very simple. It starts after sunset. People burn the fire and burn all New Year's decorations. We can burn old amulets and religious decorations.
We put the rice-cake branches into the (sacred) fire.
Then, people at the age of yakudoshi, unlucky ages toss snacks and rice cakes. For men, ages 25, 42, and 61. For women, ages 19, 33, and 37. In addition, they consider that one year before and later of the yakudoshi bring also unluck. You have to prepare food to distribute. It means that you have to prepare for 3 years around your yakudoshi.
For the age count, you have to add a year (in your mother's uterus) to your real age and we all get a year old at New Year. For the person who was born in October, for example, he is 1 year in October, becomes 2 years old at the first New Year's day although his real age is 2 months.
They say that those rice-cakes and distributed foods bring us good health for the coming year.