The Coming of Age festival is celebrated on the second Monday of January (it used to be celebrated on January 15 until the year 1999). It is a national hoilday.

All young people who turn twenty years old in that year are celebrated on Seijin no hi. Twenty is the age considered as the beginning of adulthood. It is also the minimum legal age for voting, drinking, and smoking. Celebrations are held nationwide in every town with most of the people turning 20 participating in formal dresses.