by event
Children’s Day (Kodomo no Hi)
May 5 is a national holiday of celebrations for children. Traditionally called Tango no Sekku (first [tan] day of the Horse [go] month), it is a day for celebrating the healthy growth of boys. In households with boys, symbols of strength and bravery such as carp streamers and medieval warrior helmets are put on display. People put iris stalks, which have a pungent odor which is believed to drive away illness and ill fortune, in the bath. Traditional foods include kashiwa-mochi (adzuki bean paste covered with a layer of glutinous pounded rice and wrapped in an oak-leaf) and chimaki (steamed glutinous rice wrapped in sasa bamboo leaves).
Reference site
「日本文化いろは事典」
http://iroha-japan.net/iroha/A02_holiday/08_kodomo.html
「JFみんなの教材サイト」
https://minnanokyozai.jp/kyozai/material/KKI00059/kki00059_sheet.pdf
Related site
Hinamatsuri (the Girls’Day)
http://www.tjf.or.jp/clicknippon/ja/365/event/hinamatsuri/