What is Children's Day in Japan? (Koinobori and Tango no Sekku explained)
- by MaedaYumiko
- 2 min reading time
Learn about Children's Day in Japan, its origins, and the meaning of koinobori. A simple guide to this traditional celebration.
Children's Day in Japan is celebrated on May 5th and is a national holiday dedicated to the happiness and healthy growth of children.
Today, it is a celebration for all children, but originally it was known as “Boys’ Day” and was often seen as the counterpart to “Girls’ Day” (Hinamatsuri).
The origin of this celebration comes from an ancient Chinese tradition called Tango no Sekku (端午の節句), which was introduced to Japan over 1,000 years ago. At that time, May was believed to be a season when illness and bad spirits were more common, so people held rituals to protect themselves. A plant called shobu (菖蒲, iris) was used to ward off evil.
During the Edo period (1603–1868), the meaning of this day changed. The word shobu also sounds like shōbu (尚武), meaning “respecting the warrior spirit.” Because of this, the tradition became associated with samurai culture and came to celebrate the growth and strength of boys.
Even today, families with boys often display kabuto (兜, samurai helmets), armor, or warrior dolls. In my own family, we started displaying a small kabuto after my son was born. It is not very large, but it is made of traditional Seto ceramics (Seto-yaki). Our koinobori were handmade by my aunt, and the wall decoration was a gift from my parents. It may not be as grand as traditional displays, but it is full of love for our child.
In 1948, this day was officially established as a national holiday called Children's Day. It is defined as a day to respect children's personalities, promote their happiness, and express gratitude to mothers. Since then, it has become a celebration for all children, not just boys.
One of the most iconic symbols of this day is koinobori (鯉のぼり, carp streamers). Carp are known for swimming upstream even in strong currents, symbolizing strength and success. Families display them to wish for their children to grow up strong and resilient.
Traditional foods include kashiwa mochi (柏餅, rice cakes wrapped in oak leaves) and chimaki (ちまき, sticky rice dumplings). The oak leaf used for kashiwa mochi symbolizes family continuity, as it does not fall until new leaves grow. I personally loved these sweets as a child and always looked forward to eating them. Even school lunches sometimes included chimaki, showing how familiar these foods are in Japan.
Unlike Hinamatsuri, Children's Day is not strongly associated with wearing kimono. However, some families take photos of their children in traditional outfits such as hakama (袴). In recent years, modern kimono and obi (帯, sash) designs have also incorporated motifs inspired by this festival.