The kind-hearted, innocent and optimistic Ba Dun is a mermaid, who was arrested as soon as he came ashore after taking human form. After escaping, he met the arrogant female president Jiang Su Su. Initially, their differences in character are the source of many misunderstandings. But soon, under the influence of the creature from the sea, Su Su not only opens up more to people, but also opens her heart. However, the feeling that arises between them becomes questionable when staying too long on land merman, starting to feel its effects.