Japanese History
Shichi Go San
Shichi-Go-San ( 七五三 - seven-five-three ) is a festival marking a Japanese traditional rite of passage for 3 and 7 year-old girls and 3 and 5 year-old boys. Because it is not a national holiday, it is held on the nearest weekend to November 15th.
In the old times, the day of November 15 (the 15th day of the 11th month) was considered auspicious and it was permanently associated with the Shichi-Go-San festival when the Shogun Tsunayoshi Tokugawa organized the rite for his son on this day.
photo credit: James Alexander Jack
Follow up:
The custom dates back from the Heian period (794-1185), when the infant mortality rate was high. At the beginning was held only by nobles and samurai and more recently, during the Meiji era, it became a popular festival.
Even if today the children’s clothing is changed, part of the dressing rituals of Shichi-Go-San were preserved. At the age of five years, the boys wore hakama for the first time…
photo credit: Steve Thoroughgood
… and at the age of seven, the girls were replacing the kimono narrow belt, worn until then, with the beautiful obi:
In the old times, the children under three years, boys and girls alike, wore only short hair and their hair was allowed to grow longer only after the age of three. Fortunately, this custom was dropped. 
On Shichi-Go-San, the parents give to the children a candy called chitoseame (thousand year candy), usually packed in a bag decorated with two symbols of longevity, the crane and the turtle.
Then the children are taken by their parents to a Shinto Shrine (the most popular in Tokyo is the Meiji Jingu), to offer thanks to the kami and to pray for health, happiness and long life.
Of course, its a great occasion for parents and photographers to take a lot of photos… so I’ve selected some of the best Creative Commons licensed photos from Flickr to augment this (rather boring) article.
