The Shichi Go San or 7-5-3 Festival is one of the uniquely Japanese festivals. Boys who are 3 and 5 years old, and girls who are 3 and 7 are taken to a shinto shrine, often in their first kimono, and the parents pray for their continuing good health and prosperity. The numbers, especially 3 and 7, are lucky numbers in Japan, and until the 20th century Japan was a thoroughly feudal nation with a higher childhood mortality rate. Since bacterial pathology was then unknown to them they often blamed death on evil spirits, and when the kids became 3, 5, and 7 years old they thanked the gods for their children's good health. A sweet candy called chitose-ame is also often bought for them, in a bag with cranes and turtles, 2 more symbols of long life. Other gifts are also given to them, as you can see some samples like the Japanese animation cat Doraemon.
Five-year-old boys and seven- or three-year-old girls are taken to the local shrine to pray for their safe and healthy future. This festival started because of the belief that children of certain ages were especially prone to bad luck and hence in need of divine protection. Children are usually dressed in traditional clothing for the occasion and after visiting the shrine many people buy chitose-ame ("thousand-year candy") sold at the shrine.