In her previous life, she was Yue Lao's little fairy child.
In his previous life, he was a mortal scholar.
In this life, she is a little demon in the water who transforms into a human being, Zi Ning
In this life, he is the prince Shangguan Yifan.
Who saved whom in this life, who fell in love with whom, who let him down, and can he stay with only one person for the rest of his life?