Love this manhwa so much! It's the story of the little mermaid but instead of a mermaid it's a merman who is the King of the Sea. The latest chapter released in English is Ch 36. Highly recommended by soula81!
From Udon Entertainment:
Remember the tale of the little mermaid that fell in love with the dashing human prince? Now, imagine the roles reversed, as a romance blooms between the beautiful Evyione and a dashing young merman. It's a unique twist on a timeless tale that is sure to leave you spellbound.