Tango no Sekku/Kodomo no hi
>How to Draw Japanese Things
菖蒲
Shoubu
Japanese iris the symbol of martial spirit
May 5 is Kodomo no hi（子供の日/Children's Day）. Originally it was called Tango no Sekku(端午の節句), this day was Boys' Day, Girls' Day being on March 3.
After WW2, May 5 was designated holiday called Children's Day to honor both boys and girls.
On this day, shoubu(菖蒲/Japanese iris) leaves are used to decorate roofs and are put in a hot bath as a charm against evil spirits and diseases; thus, this day was originally called Iris Festival.
Families with boys hanging out koi-nobori(鯉幟/carp streamers), shaped like carp, historical warrior dolls are displayed on tiers set up in the alcove. Traditional treats for this special day, chimaki(粽・茅巻/ricedumplings wrapped in bamboo leaves) and kashiwa-mochi(柏餅/rice cakes wrapped in oak leaves), are prepared.
This day was traditional event at the Imperial Court in the Nara period(奈良時代 710-784), the mounted archers shot arrows to exorcise Hoodoos at May 5.
鯉幟
Koi-nobori
( Carp streamers)
Carp have the strength to swim even up waterfalls and have long been taken as symbols of success in life.
egend has it that a carp which swum up a waterfall turns into the dragon, and learns to fly in the sky.
粽・茅巻
Chimaki
柏餅
Kashiwa-mochi
Oak leaves are the symbol of descendant prosperity.