Simcheong, Momeul Bachiomnida

A man, Shim Cheong, cast into the deepest depths of the sea by humans' greed to calm the raging waves. Contrary to what he had imagined from the rough waves, the Dragon King he met in person was exceedingly benevolent. The innocent and pure Shim Cheong gained the Dragon King's favor, and the two began to grow close in both body and soul...

(Source: Naver, translated)

Note: The second story in Coconut's Jeonradonghwa Danpyeonseon (전라동화全裸童話 단편선) Collection.