Lin Xiaoxiao is a cheerful, outgoing sports major. One day, while browsing an antiques market with her roommate, she spots a jade pendant that immediately catches her eye. With her roommate's help haggling, she buys it for a few hundred yuan and puts it on. What she doesn't know is that the pendant has a twin, whose owner is Xia Fan, the aloof, brilliant archaeology student at her university.
And so begins a “disaster” set off by cold water! Whenever Xiaoxiao comes into contact with cold water, their souls instantly switch bodies.
The whole university soon witnesses some astonishing sights: the usually icy Xia Fan scratching his head over calculus problems in class and blurting out, “This is harder than a fight!” Meanwhile, the energetic Lin Xiaoxiao plays basketball with a blank expression, sinking a perfect three-pointer with precise physics calculations. As they struggle with the confusion of “Who am I?”, they have to clean up each other's messes. From sworn enemies who can't stand each other, they become two people sharing the biggest secret of their lives.
Through one hilarious body swap after another, they enter each other's utterly different worlds, supporting one another as affection quietly takes root. But when the pendant's ancient secret and the danger it brings begin to surface, the two forced-together rivals discover that their meeting was no accident, and that their unusual bond will become their greatest strength in protecting each other.
