In late April and early May, the skies of Japan are decorated with vibrant, fluttering carp streamers.These are called Koinobori, and they are displayed every year to celebrate Children’s Day on May 5th. Far more than just decorations, Koinobori carry deep symbolism, representing parents’ hopes for their children’s health, strength, and future success. Origin and Symbolism The tradition of Koinobori began in the Edo period (1603–1868), when samurai households displayed banners to celebrate the birth of boys.Over time, these evolved into carp-shaped streamers, inspired by a Chinese legend: A carp that bravely swims upstream and climbs a waterfall transforms into ...