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, also known as , originally referred to an annual ceremony held at the Japanese imperial court on May 5. It was one of the five annual court ceremonies called . Since the Kamakura period (1185–1333), when the samurai class seized power, has become an event to ward off evil spirits for samurai boys. Japanese armour, (helmets) and Japanese swords were displayed in houses from the Kamakura period to the Muromachi period (1333–1573). From the Edo period (1603–1867), were displayed in homes, (carp streamers) were hung in gardens. From this period, the custom of decorating houses with offerings on spread to the peasant and classes, and paper began to be displayed. Other festivals celebrated on the same date in the lunisolar calendar include the Duanwu Festival or Tuen Ng Festival (Cantonese) in mainland China, Hong Kong, Macau, and Taiwan, the Dano Festival in Korea, and in Vietnam.
Etymology
means and is a simplified form of , referring to the Chinese zodiac name for the fifth lunar month. Days of the week also have zodiac animals. Thus, originally meant 'the first horse day of the fifth month'. However, is a homonym for in Japanese, so during the Nara period the meaning shifted to become the fifth day of the fifth month. means a seasonal festival. There are five , including Jinjitsu (January 7), Jōshi (, March 3), Shichiseki (, July 7) and Chōyō (, September 9), along with . marks the beginning of summer or the rainy season.
History
thumb|right|, and . "Japanese Festival in Honor of the Birth of Children" from Sketches of Japanese Manners and Customs, by J.M.W. Silver, illustrated by native drawings, published in London in 1867
Although it is not known precisely when began to be celebrated, it was probably during the reign of the Empress Suiko (593628 AD). In Japan, was assigned to the fifth day of the fifth month after the Nara period.
was originally a day for women to purify the house by thatching the roof with irises, which were believed to be effective in repelling evil spirits, and for women to rest their bodies, but it was changed to a day for boys in the Kamakura period (1185–1333) when the samurai class took control of the government. The reason for this was that the calamus was a plant that represented the samurai because its leaves were shaped like the blade of a Japanese sword, and the word , which means , had the same pronunciation as and was therefore considered an auspicious plant for the samurai. Since this period, (Japanese horseback archery) was held on May 5 as a way to ward off evil spirits.
The custom of displaying miniature Japanese armor and (helmets) on Children's Day, called , has its origins in the Kamakura to Muromachi periods (1333–1573). Samurai used to take their armor, , and Japanese swords out of their storage boxes in May before the rainy season to take care of them. Since this was the time of the , they began to display armor, , and Japanese swords in the hope of protecting their children.
In the Showa era (1926–1989), the popularity shifted from samurai dolls to miniature armor, and since the 21st century, miniature have become popular, probably due to the size of Japanese houses. The oak leaf used for is said to be a tree whose old leaves do not fall off until new leaves appear, and is considered a good-luck charm representing prosperity of offspring.