So-Ah works as a teacher at a local school. She was curious about Boo Young-Suk, a student with a sinister aura who is always present on the attendance list but no one calls him by name. The more she tries to get Boo Young-Suk back to school, strange things begin to happen at school.
Tells the romance story of a girl named Hye Ri. She goes to Gangwon Province on a graduation trip with her friends. There she meets a mysterious man Woo Hyuk who runs a guest house. She gets attracted and closer to him and decides to name him “the mermaid prince”.