Pond of Ryu and Yon
[Origin]
A long time ago, young Ryu went on a trip and stopped by at Jeju. While he lost his mind at the sight of the wide and vast sea of Suguipo, Yon, the daughter of the dragon king of the sea fell in love with him. Yon tried to convey her feelings by sending him a carp, Buu, but Ryu had already returned to the mainland. However, Buu happened to be a very faithful vassal and swam up the waterfalls and streams to deliver the letter from Yon. Naturally the dragon king of the sea was angered by this news, and dried up all the water in the streams. But this couldn't prevent the couple from loving each other deeply. Eventually, the two managed to convince the king, but Ryu couldn't live in the water, while Yon couldn’t live out of it, so the king decided to turn them into a pair of mandarin ducks, and from then on they lived in the pond and the waterfall next to the dried-up streams, and the king had Buu stand guard over them. Just like Ryu did, clap your hands to gather the carp descendants of Buu, and you can see that there's still no water at the dried up streams.