The story is narrated by Lin Yi (Lin Gengxin, “Young Detective Dee: Rise of the Sea Dragon”), who, at the pic’s start in 2013, appears to be living every Chinese person’s American dream as a New York IT exec. When he receives the wedding invitation of his old flame Xiaozhi (Zhou Dongyu), he returns to Beijing for the first time in 10 years. Back at primary school in 1993, transfer student Xiaozhi (Zhang Zifeng, a dead ringer for Zhou), is assigned to sit next to Lin (Li Jiacheng, cheeky), initiating a meet-cute sweet enough to rot your teeth. (Lin’s boyish gallantry guarantees brownie points from distaff audiences.)