Today is 成人の日 Seijin no Hi! or as one would say in English the Coming of Age Day.
Each year, on the second Monday of January,all youths are celebrated which had/have their twentieth Birthday between the 2nd April of of the last year up to the 1st April of the current year. On this day, a ceremony will be held, which is called 成人式 Seijin-shiki, with which the youths shall be reminded of the future responsibilities of their future. Often, these festivities include speeches of important personalities of the village/city. Another highlight are for sure the breathtaking (and mostly really expensive) traditional attire of the young women. Young men are usually seen in black suits and only in rare cases in Kimono.
In Japan, adulthood is reached with the completed 20. year of life (according to § 4 of the Japanese Civil Law). Furthermore, Seijin no Hi has been counted as public holiday since the year 1948.
All the best to all the young adults and lots of strength and joy in their future! 😉