noun
baby's first seasonal festival
Refers to the first celebration of traditional annual festivals (such as Hina Matsuri for girls or Tango no Sekku for boys) after a child's birth. Often involves special displays and family gatherings.
娘の初節句には、ひな人形を飾りました。
For my daughter's first Girls' Festival, we displayed hina dolls.
初節句のお祝い
For the first Boys' Festival celebration, a samurai helmet was given by the grandparents.