How can a mermaid from the Joseon era survive in modern-day Seoul? Shim Chung is a mermaid who finds herself transplanted to modern times. She is caught by Heo Joon Jae, a charming but cold con artist who is the doppelgänger for Kim Moon, the son of a nobleman from the Joseon Dynasty. But in the present time, Joon Jae works with Jo Nam Doo, a skilled conman who guides Joon Jae to become a genius scammer. But Joon Jae’s friend, Cha Shi Ah, who works as a researcher at KAIST, may be Chung’s only hope for surviving in her strange new world.

Fair Princess Jungmyung lives a life of the highest privilege, until her half-brother Prince Gwanghae executes the rightful crown prince and usurps the throne. Exiled from court, Jungmyung goes under disguise as a man and learns to adapt to life as a commoner — never forgetting Gwanghae’s wrongdoing. But amidst rampant corruption throughout the kingdom, can Jyungmyung exact her vengeance, restore order and take back her rightful place in the palace?