Japanese Fish Flag: Koinobori. In Japan Fish Flags Are Symbols For Children's Day. Stock Image

Celebrating the double fifth—the fifth day of the fifth month — originally known as Tango no Sekku (Boy’s Day) formed a pair with Hinamatsuri (Girl’s Day), which is celebrated on the double third. Tango no Sekku expanded to incorporate good wishes for both boys and girls, and the holiday’s name officially changed to Kodomo no hi (Children’s Day) in 1948. The flags are a symbol of each family’s hope that their children will exhibit vigour, and success. The colours of Japanese fish flags correspond to each member of the family. The largest fish in the strand, the black one, is the father’s, and the red one is the mother’s. The blue carp symbolises the eldest child and the varying colours that ensue belong to the younger children in the family.