An art history lecturer, unfairly disgraced by her superior for refusing to certify a suspicious painting, endeavors to set the record straight by exploring the mystery of a 16th-century artist using a diary that may lead her to the genuine painting.

The television series centers on the love story of Heo Joon Jae, who is a clever con-man, and a mermaid named Shim Chung, who falls in love with him.