Six years ago, Cheng Shuning left with her children, taking care of her sickly elder son alone. A rainy-day mix-up of children reunites her with the amnesiac Lu Tingshan. A pair of identical twins unveils a long-concealed secret, as the truth of that year's accident slowly comes to light. Moving from estrangement and testing each other to gradually letting down their guard, the two accompany the children together to reclaim a warm fate and piece together their home.