Yana Jeong, a typical girl, runs into a strange man who's out of breath during one of her part-time jobs. Little did she know that this was Kai Shim, the son of the CEO of a large jewelry corporation called Inoroo, who also happens to be a merman. Yana coincidentally runs in Kai again when she ends up working as a waitress at his birthday party, where a series of accidents lead to the two of them meeting each other again. Will Yana be able to keep up with these unexpected events happening one after another?