Have you seen Koinobori (carp streamers) in Japan?

You can see Koinobori from April through early May to celebrate Children’s Day on
May 5th.

Do you know what it means?
Koinobori are flown above the roofs of houses to pray for health and successful future for a baby boy.  It has started since the Edo period. At that time, there was a custom to raise a banner at the entrance when a boy was born in a samurai family. Later, people came up with an idea to raise Koinobori because Koi (carp) have a very strong life force as Carp can live not only fresh water but also both pond and bog.

The biggest black Koinobori (Magoi) means the father, red one (Hikgoi) is the mother and other small Koinobori in green and blue are children.