Pei Tian, a young and stubborn sophomore, spent Christmas Eve alone in the southern hemisphere and met Cui Hao, who had missed his friend's wedding. The two returned to their respective lives after spending an unexpected vacation in a strange country. Pei Tian entered the Hong Kong branch of an American IT company as an intern on the recommendation of a university professor. Cui Hao happened to be transferred back to Hong Kong to work, and the two met again. In this dimly lit city, Pei Tian knew for the first time that fate was inevitable.