In Japan, we generally celebrate May 5 as "Children's day",
which is one of Japanese national holidays.
The another name of "Children's day" is "Boy's festival".
This day was originally celebrated in order to wish
the healthy growth of the boys in the family.
Koinobori (carp streamers) are flown outside
as symbol of strength and courage and
miniature samurai warrior helmet (kabuto)
is displayed inside the house.