'Children's Day' or Boy's Day. A boys' counterpart to the girls' hina-matsuri. It takes place every year on the third gosekku, the 5th day of the 5th month (May) and features displays of model samurai armour and helmets as well as gogatsu ningyo; 'May dolls', all symbolising courage and loyalty. Two characters often represented by dolls are the ferocious Shoki-san, a Chinese hero shown crushing a devil underfoot and Kintaro, a devoted son who leads a bear and carries a hatchet over his shoulder. Cloth streamers in the shape of carp (magoi, black carp for the father, higoi, red carp for the mother) representing bravery and longevity are flown above the house on poles.
A Popular Dictionary of Shinto. Brian Bocking.