The probability of them meeting was one in a billion. In a parallel time and space, the cold and unapproachable top student Ye You Ning encounters the bright and sunny Xia Wen Si. Through an unexpected opportunity, Ye You Ning of the present connects with Xia Wen Xi from the year 2006. Their encounter leads to a sweet romance and a chance to relive high school, to meet old friends again and to experience the taste of first love.