Kodomo no Hi: The Unique Ways Japan Celebrates Its Children’s Day

May 3, 2025

BY Clairine Daphne

Out of all the holidays that make up Golden Week, the last holiday of “Kodomo no Hi” or “Children’s Day” might be the most personal and heartwarming. Celebrated annually on May 5th, this holiday wishes for the health and happiness of children as well as expresses gratitude to the mothers who raised them.

However, even if you did not know about Kodomo no Hi beforehand, you might’ve noticed the carp-shaped flags hung on balconies throughout Japan around the same time, making for a colorful parade as you walk down the street. These iconic decorations are an essential part of the celebrations and go beyond the sake of memorable aesthetics, much like the dolls displayed on Girl’s Day on March 3rd.

That said, did you know Children’s Day was originally a day to celebrate boys? Read on to learn more about the unexpected history that shaped this holiday and its unique celebrations – which you can even join in on!

Japanese Koi Nobori Carp – Photo Credit: Lifebrary

History

Kodomo no Hi actually started off as a completely unrelated event for women to rest their bodies and purify the house by thatching the roof with irises, whose fragrance is believed to ward off evil spirits. One of five annual ceremonies at the imperial court, this event, known as “Tango no Sekku,” centers around the Chinese belief that the 5th month of the lunar calendar is an inauspicious month where disasters – from wars to personal misfortunes like catching diseases – are likely to happen. As a result, Heian period (794-1185) nobles would wear irises in their hair and give each other medicine balls with irises wrapped around them. Other customs like eating “chimaki,” a type of sticky rice dumpling, and drinking a brew of dried iris roots can still be observed today.

But the current form of Kodomo no Hi largely owes it to the Kamakura period (1185-1333) when the samurai class became the ruling body of Japan. Because the iris, which resembles the blade of a Japanese sword, is the symbol of the samurai, the day is instead changed into a celebration for boys.

A hotel’s doll display featuring samurai weapons, equipment, and typical Kodomo no Hi food offerings – Photo Credit: Hotel Ryumeikan Tokyo website

Many present-day customs are established from this time onwards, for instance, displaying samurai armor, helmets (“kabuto”), and swords in the home to protect boys from evil spirits. Originally, this was because samurai used to take out their equipment from storage in order to ventilate the area before the rainy season, which coincides with the time of Tango no Sekku.

By the late Edo Period (1600-1868), the decorations extended to displaying dolls of military commanders, and the custom spread to the common folk who began displaying paper kabuto in their own homes. The carp streamers, or “koinobori,” originated in this period and are derived from the banner flags bearing the crest of samurai families. Taking a bath with irises also became a common feature of the festival from this period onwards.

After Japan switched to the Gregorian calendar, the date was moved to May 5th to reflect how it took place on the fifth day of the fifth month of the lunar calendar. In 1948, the day was made a national holiday by the Japanese government, which also expanded it to celebrate all children and families as a whole. In reality, though, many families still celebrate Kodomo no Hi as the Boys’ Festival, and most of the withstanding traditions were first established for the sake of the health and success of boys.

How to Celebrate Kodomo no Hi

Decorations

A progression of smaller koinobori represents the family structure – Photo Credit: JACCC official website

Koinobori: The colorful carp-shaped flags hung outside homes are meant to pray for the strength and success of children. Based on the ancient Chinese legend, where a carp became the only one out of a school of fish to make it up a waterfall and turn into a dragon, it became seen as the symbol of courage, perseverance, and determination. The banner flapping in the wind can be said to resemble a carp swimming against the current to steadfastly reach its goal, much like in the legend.

The koinobori are arranged in order of the family hierarchy, with corresponding colors and sizes to go with them. A large, black koinobori on top represents the father, whilst the red one below belongs to the mother. Then, there’ll be one carp for each child in order of decreasing age, with the oldest often being represented by a blue carp. The koinobori are hoisted from as early as after the spring equinox (late March) to as late as June.

A typical “gogatsu ningyo” setup – Photo Credit: Tougyoku website

Gogatsu ningyo: A “doll” made up of miniature replicas of samurai armor, weapons, and kabuto, which are meant to ensure the health and safety of children. During samurai times, it also symbolizes the hope of raising strong and brave boys. Since this full setup can get expensive, at least the kabuto would be displayed by families with boys. Sometimes, children would make kabuto out of origami that they can actually wear.

From the Showa period (1926-1989), these miniature armor became more popular than the “samurai dolls,” which are miniature figurines of famous figures from Japanese emperors to folk heroes like Momotaro and Kintaro. Displaying these figures represents a desire for boys to grow up strong, courageous, and successful.

Food

Below are some of the common foods eaten during Kodomo no Hi, although it might be more common to eat one over another depending on the region.

A plate of chimaki and kashiwa mochi on top of colorful koinobori – Photo Credit: Kyoto Shimazu website

Kashiwa mochi: Sticky rice cakes, or mochi, stuffed with red bean paste and wrapped in oak leaves. As oak trees do not shed their old leaves until the new ones have grown, eating kashiwa mochi symbolizes hope for the continued health and prosperity of the family for generations to come. It’s more common to eat kashiwa mochi rather than chimaki in the Kanto region.

Chimaki: Another steamed mochi dish that is wrapped in bamboo leaves instead and is either triangular or stick-like in shape. It originated in China and spread to Japan during the Heian period, where it was believed to ward off evil spirits and prevent disasters. Additionally, bamboo represents strength, prosperity, and resilience in Japan, which definitely coincides with the qualities parents often wish for their children on Kodomo no Hi. In the Kansai region, it’s more common to eat chimaki rather than kashiwa mochi.

Shobusake: Where iris leaves or its thinly sliced roots are simply steeped in cold sake. This treat for adults makes use of the irises’ amulet-like effect of warding off evil but also its medicinal properties. Iris roots are used in Chinese medicine and serve a variety of purposes, including treating digestive issues, respiratory diseases, and for detoxification.

Activities

It’s also an old custom for families to take iris baths, which, again, promotes health and is believed to bestow good fortune. Supermarkets would usually sell packs of iris leaves for this purpose, and some bathhouses might even offer iris baths, or “shobu-yu,” on this day.

As Kodomo no Hi falls during Golden Week, families might go on trips or return to their hometowns to celebrate. They might also do family-oriented activities like visiting zoos, amusement parks, and festivals with koinobori displays, like the ones introduced below:

5 Koinobori Festivals to Celebrate May 5th

Uzuma no Koinobori (Tochigi) (early March – mid-May):

Ride a Japanese gondola boat with more than 1,000 koinobori swimming overhead. Take in the cityscape of Edo period warehouses on either side of the Uzuma River, and slip further back in time with the boatman’s singing and their stories about Tochigi City and the Uzuma River in between. Afterward, explore the stylish cafes scattered along the nostalgic streets or experience feeding the actual carp living in this historic river.

Google Maps: 2-6 Yamatocho, Tochigi, 328-0037

Website: http://www.k-yuransen.com/#

Koinobori flapping underneath Tokyo Tower – Photo Credit: Visit Minato City official website

Tokyo Tower 333 Koinobori (Tokyo) (late March – early May):

This iconic landmark becomes even more picture-perfect with the 333 koinobori, which represents the actual height of the tower in meters surrounding its main entrance. Try and see if you can spot the impostor amongst the carp: a giant Pacific saury, which symbolizes the connection between the tower and the town of Ofunato in Iwate Prefecture. This special saury streamer is a show of support for the town’s reconstruction efforts after the 2011 Great East Japan Earthquake and has been part of the decorations ever since.

Google Maps: 4 Chome-2-8 Shibakoen, Minato City, Tokyo 105-0011

Schools of koinobori swimming above Tatebayashi’s Tsuruuda River, with cherry blossom trees running alongside it – Photo Credit: Visit Gunma official website

Tatebayashi Koinobori no Sato Festival (Gunma) (late March – mid-May):

Because the koinobori is on display here for a relatively long period, it gives you the chance to appreciate Tatebayashi’s beautiful seasonal flowers at the same time – depending on when you choose to go. Walk under the cherry blossom trees lining the Tsuruuda River, where rows and rows of colorful carp banners have been hung just over the water. With 5,000 carp streamers spread over 5 locations in the city – certified as the world record for most koinobori in 2005 – why not hit up all the spots and Tsutsujigaoka Park while you’re at it? There, 10,000 azalea seedlings are in full bloom from early April to early May every year, the sight of which is sure to brightly color your memories for years to come.

Google Maps: Shiromachi, Tatebayashi, Gunma 374-0016

Website: https://www.visit-gunma.jp/en/spots/tatebayashi-koinobori-carp-streamer-village-festival/

Koinobori festival at Tsuetate Onsen with a view of the river and surrounding mountains – Photo Credit: Tsuetate Onsen official website

Tsuetate Onsen Koinobori Festival (Kumamoto) (early April – early May):

In this tiny hot spring town hidden in the mountains of Kumamoto Prefecture, 3,500 carp streamers from all parts of Kyushu gather above the town’s central river. Claiming to be the birthplace of the koinobori festival in Japan, go back in time by wandering through the unchanged heart of the town. Watch the carp billow in the occasional steam from the hot springs and heal your inner child in this town, still very much embraced by history and nature. Walk far enough downstream, and you just might spot Momiji Bridge, where many carp-shaped ema, or wooden plaques for writing down wishes, have been hung from the roofs – and feel free to hang one yourself for some luck in love.

Google Maps: 3415 Shimojo, Oguni, Aso District, Kumamoto 869-2503

Website: https://tsuetate-onsen.com/tsuetate_spot

Koinobori Festa 1000 (Osaka) (late April – early May):

For a true Japanese matsuri vibe, combined with some good old family fun, don’t miss out on this koinobori festival if you’re in the Kyoto or Osaka area. As its name suggests, watch 1000 koinobori swimming across the Akuta River as you peruse the food stalls set up along its riverbanks. Lay down a picnic mat and enjoy your chimaki, shaved ice, or okonomiyaki before your kids – or yourself – inevitably drag you to one of the game stalls. If it’s not from all the jumping at the bouncy house, then the drum and dance performances will definitely get your heart pumping. Enjoy splashing up and down the riverbank with your family or friends for a reminder of simpler, carefree days.

Google Maps: 12 Seifukujicho, Takatsuki, Osaka 569-1132

Website: https://koinoborifesta1000.jimdofree.com/

Children running below a sky full of koinobori – Photo Credit: Takatsuki Kankou official website

Whether you have kids or not, Kodomo no Hi is a celebration that can be enjoyed by everyone. All the festivities, with their colorful decorations and unique food offerings, are sure to make your Japan trip that much more vibrant and memorable. And the number of festivals happening nationwide might just make you want to go on a road trip to hit up all the spots, inviting you to hidden gems of towns you’d otherwise overlook.

So, if you’re in Japan during the lead-up to Kodomo no Hi, why not sample a chimaki or kashiwa mochi (perhaps with a bottle of shobusake to down the sweetness) and impart some good wishes to the families around you? Let the children grow strong, healthy, and happy. The world becomes a better place when children are able to embrace their unique personalities and reach their dreams, after all.

 

Our mascot UmaChan wants to make as many friends as possible all over the world, so why not download the OFFICIAL Umachan Coloring Book for Kodomo no Hi?? Your kids will love it, and it would be something perfect for them to do on your flight to come see us in Japan.

 

Featured Photo Credit: Visit Gunma official website

Regardless of where you go to celebrate Kodomo no Hi, be sure to check out some of our food tours to get a truly local experience in Japan!

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