Introverted girl Xu Yuning was on duty in the library when she fell into a suffocating nightmare in the deep sea and was rescued by the legendary mermaid.
The next day, Cheng Xiling, a transfer student with sea-blue eyes, became her deskmate.
When the quiet campus routine was broken by the whispers of the deep sea, she discovered that the gentle protection of her deskmate had long been closely linked to her destiny.
Concept: If the dream is something that happened before