According to Chinese mythology carps swim up river to become dragons. The Koinobori flapping in the wind resemble carps swimming up stream. They represent a young child's journey to becoming a dragon (successful adult).
The black carp represents the father, the red carp represents the mother a blue carp is added for each child (traditionally each boy).
Children's Day is part of the Golden Week mega holiday in Japan. It takes place on May 5th each year.
Children's Day or Boy's Day?May 5th was previously known as Boy's Day (Tango no Sekku). It has been celebrated as such since the year 628. Recently, the government announced the day would be changed to Children's Day. They stated the new meaning of the day would be "to respect children's personalities and to give thanks to mothers for raising children".
This has generally confused people in Japan for several reasons:
1. There's already a Girl's Day (Hina Matsuri) on March 3rd.
2. Mother's Day is celebrated in Japan as in the West (second Sunday in May). There's no tradition of giving thanks to Mothers on May 5th.
3. The traditions and symbolism of May 5th is related to boys. These traditions are thousands of years old and are deeply entrenched.
4. The Japanese government is in the habit of changing the meaning of public holidays on a regular basis.
These factors have meant that most people still celebrate the day as Boy's Day (Tango no Sekku).
How is it Celebrated?Boy's Day is a special day for boys in the family. It's a day when young boys think about their future. The symbolism of the day is intended to honor boys and hope that they will grow up healthy and strong.
Koinobori carp flags are put up in April and kept flying for about a month.
Kodomo No Hi cakes and deserts also have a carp theme.
It's also common to eat kashiwa mochi (mochi filled with red bean paste wrapped in oak leaves).
On May 5th families display traditional samurai helmets (Kabuto).
It's also common to make an origami helmet for young boys on this day.