The film tells the story of Yang Fan, a marine biology researcher, who fell into the sea while chasing mermaids and was rescued by Xiaoyu, a mermaid in human form. After experiencing exploitation, suspicion, deception, and confession, Yang Fan and Xiaoyu fell in love and eventually saved each other. The film aims to convey the value of "love and harmony" by telling the cross-racial love between Yang Fan and the mermaid Xiaoyu.