This is Koinobori, meaning “Rising Carp” streamer shaped.
This fish is carp. I know it is exported from Japan with very expensive prices sometimes more than 1 million Japanese yen to the World.
Why carp? There seems to be many stories, but one of them is in Kyoto, Carp was or is still considered by a messenger of God rising up the river to a villege where disastered by calamity.
When I was small, my parents has set 3 or 4 carp made by textile with different colours such as black, red, blue or green over the roof of the house. This customs was started 200 or 300 years ago during Edo era by traditional samurai families.
We can see those Koinobori also in Miyagi.
This is Higashi Matsushima, blue carp only or red only.
In Taiwan also, Koinobori is rising.
Koinobori can be seen nationwide in Japan during early May.
Please go out to look for.