For Kodomo No Hi (Children's Day), families raise colorful carp-shaped "Koinobori" flags, one for each member of the family. The largest and uppermost flag represents the father, followed by the mother, and small carp to represent children.

Children's Day (Kodomo-no-hi or Tango no Sekku) is one of the most popularly celebrated national holidays in Japan. Until recently, Tango no Sekku was the boys' day (also known as Feast of Banners) while the girls' day (Hinamatsuri) was celebrated on March 3 (known as Doll Day). In 1948, the government decreed this day to be a national holiday to celebrate the happiness of all children and to express gratitude towards mothers. It was then renamed Kodomo no Hi. 

May 5th marks the beginning of summer on the old lunar calendar and the begining of the 5th month, which according to the Chinese calendar was set aside to be a month for purification. To expel evil spirits and celebrate the future of their sons, families hoist koinobori (cloth carp streamers) from balconies and flagpoles. Gogatsu ningyo (5th Month Dolls) are displayed in homes and store windows with images of Kintarou, usually riding on a large carp, and a traditional Japanese samurai helmet, a Kabuto.

Kintarou and the Kabuto are both symbols of a strong and healthy boy. Kintarou (金太郎) is the childhood name of a hero of the Heian period, famous for his strength as a child. It is said that Kintarou mounted on a bear, instead of a horse, and played with animals in the mountain when he was a young boy.  Some children may also take shyobuyu (a bath with floating iris leaves), and eat kashiwa-mochi (a rice cake wrapped in an oak leaf ) and chimaki (a dumpling wrapped in bamboo leaves).
 

Carp, samurai, irises, oak trees, and bamboos all symbolize strength