Plot: Shim Chung is a mermaid who follows her one true love, a nobleman’s son named Kim Ryung from the Joseon Dynasty, to modern-day Seoul. Ryung’s modern doppelgänger is Heo Joon Jae, a highly skilled scam artist who first becomes interested in Shim Chung because of a jade bracelet worth $6 million that Shim Chung wears. With nowhere to go, Shim Chung is taken in by Joon Jae, who also finds his con partners, Jo Nam Doo and Tae Oh, hiding out in his home from a vengeful past victim of their scams. Shim Chung discovers a rival for Joon Jae’s heart in Cha Shi Ah, a researcher at KAIST who deals with ancient artifacts. When a dangerous killer named Ma Dae Yeong, sent by Joon Jae’s stepmother, who wants to make her own son the heir to Joon Jae’s fortunes.

Main cast: Shim Cheong is a mermaid. She follows Joon-jae to Seoul after developing feelings for him in Spain. He names her Shim Cheong, which means "extremely stupid", as she is highly ignorant about the common things on land. She has super strength and the ability to read and erase one's memories.
Heo Joon-jae is a con-artist who uses his wits and looks to conduct scams on people of the privileged class of the society. He meets Shim Cheong, a mermaid and falls in love with her, he is able to read her thoughts. He wants to change the ill-fate that chases Dam-ryeong and Se-hwa.

Review: It is my first Kdrama and I really enjoyed it. It was a mix of romance, comedy, action and fantasy which I loved. — It was just super fun to watch. Another thing I loved was the chemistry — The two leads were amazing. I never got bored. Every episode was interesting.