There are many festivals, events, and circumstances where it is traditional to wear a kimono in Japan, even though Western clothes have become prevalent in much of day to day wear:
1. Birth of a child.
In Japanese culture, as in many others, the birth of a child is considered a milestone. When the child is between 30 to 100 days old, the family visits a certain shrine to commemorate the birth of the child. This is called "miyamairi." If the baby is a girl, she wears a brightly colored velvet kimono, while a boy wears a black kimono embellished with the family crest.
2. Shichi-Go-San Festival.
“Shichi-Go-San” stands for Seven-Five-Three. It is a festival usually held on November 15, and it celebrates Japan's children. For this occasion, parents dress their children in kimonos and take their 3-year old and 5-year old sons, and 3-year old and 7-year old daughters to a Shinto shrine to pray for good fortune and health. These ages are celebrated not only because odd numbers are considered as lucky numbers in Japan, but also because they mark specific cultural milestones in a child's growth. In the past, children's heads were shaved until the age of three, when both boys and girls were allowed to grow their hair. The age of five for young boys marks the wearing of his first hakama and haori, while the age of seven celebrates a young girl’s first obi - the traditional silk kimono belt. Until then, girls tie their kimonos with a simple cord.
3. Coming-of-Age Day.
On the second Monday in January, Japan celebrates the coming of age of young men and women who are turning twenty. For this celebration, women usually dress in zori sandals and a furisode, which is a colorful kimono with very long sleeves, while men wear a traditional dark kimono with hakama and a haori jacket. Despite the formality of its traditional clothing, Coming-of-Age Day is a holiday often celebrated by drinking and parties that go on late into the night. In a purely fashion sense, it is not unlike homecoming or prom, where young adults dress in formal clothes and celebrate on their own, away from parents and older adults.
The Japanese also have a traditional garment for wedding ceremonies. The bride wears a shiromuku, which is an all-white ultra-formal kimono, and a tsunokakushi, a Japanese wedding headpiece. White is a symbol of purity and new beginnings, and sometimes shiromuku also have white-on-white embroidery of animals like the phoenix, a traditionally feminine symbol of elegance and nobility. For a colorful splash during the reception, brides can wear an uchikake, a brilliantly colorful kimono left untied. The groom, on the other hand, wears several layers: kimono undergarments, a black and white kimono with the family crest, and a haori and hakama pants as outerwear. The bride's female relatives and friends wear furisode or tomesode depending on marital status.
5. Parties and personal ceremonies.
For formal parties as well as traditional Japanese ceremonies like flower arranging and tea ceremonies, the "tsukesage" is the historical kimono of choice. It has patterns following the hemlines and extending up the sleeves, an elegantly subdued alternative to some of the more brilliant and heavily patterned kimonos. The "houmongi," meaning "visiting kimono," is for women going out to formally visit their friends and colleagues.