The second Monday of January is “Coming-of-Age Day.” Seijin no Hi in Japanese (Adult Day). First established in 1948, this is a day to celebrate the transition from youth into adulthood and congratulate any young people who have turned 20 years old.
Special Coming-of-Age ceremonies are held in public spaces and people welcome the newly minted adults as members of society: from that day on, they must be treated as adults and are given all the rights of citizenship including voting and legally drinking alcohol and so forth.
Celebrations take place in temples and public venues like shrines, city halls and offices with formal dress like kimonos and speeches and followed by parties with friends and family.
Here’s a video from YouTube which reveals the look of the kimonos with their fur lining:
