In Japan, there is an event called Hinamatsuri, also known as Girl's Day, in March for parents to pray for the growth and health of their daughters. Every year, the houses where girls are born display hina dolls depicting the Kyoto-era Imperial court. In some regions, dolls are floated down a river each year. In Japan, it has long been believed that rivers have the power to purify and nurture, and so people have wished for the health of their children by representing the dolls as children and casting them into the river. While most Hina dolls are elaborately styled and kept as family heirlooms, the dolls to be floated down the river are usually made with origami-folded paper or other matierials before being placed on small wooden boats or on round saucers made of straw.