As unfair as it seems, there is no official Boy’s Day celebration in Japan. Although March 3 is Momo-no-sekku, Girl’s Day celebration (not a national holiday but recognized as a celebratory day), and May 5 is Tango-no-sekku, Boy’s Day celebration, ever since the establishment of the Children’s Day holiday in 1948, the day is meant to celebrate children and not just boys.
Growth of children is something to celebrate. As you can see from the word “children”, written子供, 子is child, 供 is offering to god. Children were considered to be “borrowed” from god, generally, until the age of 7. (There are several theories to the age.) Therefore, to live past 7 mean that they are fully member of the human world.
Despite being called Children’s Day, the day still has strong connection to Boy’s Day. Kabuto, warrior helmet, is displayed at houses with boy child. Another symbol for Children’s Day is koi-nobori, carp streamer. There are usually 2-3 carp-shaped streamers to a koinobori. When wind blows, the carp streamers look like they are swimming upstream. Carp has long been considered a symbol of a successful career; the reason for displaying them for Boy’s Day in hopes for the son to grow up manly.
Because koi-nobori is a symbol of Children’s Day, they are displayed across the country during this time of the year. Many numbers of Koi-nobori are displayed at locations with a wide rivers. Tatebayashi in Gunma Prefecture displayed 5283 numbers of koi-nobori as set in the Guinness of World Records in 2005.
Though it is not recommended for people to visit Japan during early May due to crowds everywhere, some koi-nobori are displayed as early as end of March; good timing to see koi-nobori.