Shen Muxin, an online magazine columnist, was rescued by the mermaid from drowning and thus believed the existence of mermaids. For this reason, she argued with the archaeology professor and vowed to find evidence. She returned to her hometown, Xingyue Bay, and joined the rescue team of the resort. In the team, she met An Xida who had left the sports arena and came here as a life-saving member. She accidentally noticed a mermaid totemin An Xida’s body. In order to prove that An Xida is a mermaid, Shen Muxin resorted to various methods, but a lot of jokes happened. Gradually, the two solved their misunderstandings and had feelings for each other. They finally managed to unveil the mystery of the mermaid together.