March 3 is the day of Hinamatsuri, or the Doll Festival. It's a day to pray for the healthy growth of girls. The festival is said to have its origins in the doll playing of aristocratic children of the Heian period (794-1185), which was combined with a ceremony of clearing away sin and impurities. It came to be widely celebrated in the Edo period (1603-1868).
Families with daughters put out dolls lavishly dressed in ancient courtly costumes from a week or two before the festival. Some families display only emperor and empress dolls, but it is more common to set up fifteen dolls on a platform of seven tiers. As well as the emperor and empress, the full set consists of three ladies-in-waiting, five court musicians, two ministers, and three attendants.
The display is further decorated with flowers, such as peach and rape blossoms, and a variety of sweets are offered: hishimochi (pink, white, and green diamond-shaped rice cakes), colorful sweet rice crackers known as hina-arare in pink, green, yellow, and other colors; and kusamochi, a mugwort-flavored rice cake with sweet bean-paste filling, which is said to ward off evil with the fragrance of mugwort. On the day of Hinamatsuri, there is also a custom of eating chirashi-zushi (vinegared rice mixed with various ingredients) and clam soup.