Once one of the five annual holidays held in Japan's imperial court, Tango no Sekku happens annually on May 5, the fifth day of the fifth month. In modern times, it is known as Children’s Day, or Kodomo no hi.

Originally a Boys’ Day, the holiday has a historic connection to the samurai culture. By the Nara period (538-795) in Japan, it was customary to display iris flowers — shōbu means both “iris” and something to the effect of “martial spirit” — on this day to drive evil away. When the warrior class took political leadership after 1192, Tango no Sekku became a day to promote warriors, and by extension, boys who would one day become warriors.

Until 1948, modern-day Tango no Sekku was a time to celebrate the strength and bravery of male children. Now, Kodomo no hi (children’s day) is an official day decreed by the government to pray for the health and appreciate the personalities of all kids in Japan. And although its martial origins are not present, the ritual of displaying and bathing with irises (syobuyu) still exists.

Traditions

Decorating the house with samurai helmets, called kabuto, and warrior dolls, known as gogatsu ningyo, is common. The carp also plays an important role in the holiday. Known for leaping up waterfalls in Japan, carp symbolize strength and bravery. Carp-shaped windsocks known as koinobori are hoisted as decorations — one for each boy in the family. In contemporary Japan, many cities display large-scale installations of koinobori; for example, 333-meter-tall Tokyo Tower displays 333 koinobori for Children’s Day. The flying fish also inspire other specialties, like fish-shaped desserts.

Cuisine

Among the multitudinous sweets, or wagashi, that are enjoyed for Children’s Day is kashiwa mochi, a rice cake wrapped in a pickled oak leaf. A specialty for Children’s Day, it has sweet red bean paste inside. Or, in some regions of Japan, it has sweet-miso white bean paste inside. The oak leaf is more than just decorative. Its position can be important in distinguishing which kind of kashiwa mochi is in front of you. The oak leaf wraps the sweet-miso type with the leaf right side out. The more common type, however, has the leaf wrong side out.

Kashiwa mochi has been eaten on Tango no Sekku since the Edo period. Historically, oak leaves were a symbol of luck. Some traditions even used them as a plate on which to put food for the gods. Oak leaves became a positive symbol in samurai culture, like irises, and the tradition carried over to the modern holiday. These beautiful desserts are often found ready-made in supermarkets leading up to Children’s Day as it can be difficult to find (or make) the pickled oak leaves.

Either sweet or savory, chimaki is another Children’s Day staple. Introduced to Japan from China during the Nara Period (710~794) or Heian Period (794~1185), chimaki has a long history in Japanese food culture. Made of seasoned rice steamed in bamboo, banana or reed leaves, the savory option includes meat and vegetables (possibly red snapper and chestnut), while dessert chimaki might have rice, yokan — a jelly made with sweet red bean paste, or kudzu powder.