The title, Chungking Express, is a pastiche of Chungking Mansion in Tsimshatsui and a snack bar called Midnight Express in central Lan Kwai Fong, where the mise-en-scene is based. .
Chungking Express depicts two virtually unrelated but loosely linked stories in which the paths of its characters crosses at some point in time. They are obscurely linked by location and the fact that both the male protagonists are recuperating emotionally after breaking up with their girlfriends. The element of time is essential to its narrative and draws a sense of parallelism between the two stories. The concept of time is constantly reminded through shots of the expiration date printed on the cans and digital clocks. Bordwell said the theme of time, which critics agree, is central to Wong Kar-wai's work (272).
The first story takes place mainly in a part of Tsimshatsui known as Chungking Mansion, where a number of Indian restaurants and old guest houses are located. It follows the life of a policeman named Ho Chi-wu and also known as "Cop 223" who has just been dumped by his girlfriend and desperately misses her. Cop 223 vows to reconcile with his ex-girlfriend by 1 May, his twenty-fifth birthday. Counting down to the reconciliation since their break-up on 1 April, he buys a can of pineapple, his ex-girlfriend's favourite fruit, with the expiration date of 1 May every day. Coincidentally, that is also the same day which a mysterious woman, with a blonde wig, plans to complete her drug deal. On 1 May, Cop 223 finally realises that his ex-girlfriend is not going to return to him and ends up eating all the thirty cans of pineapple in a night while the blonde-haired woman's drug deal backfired. Both of them meet in a bar and spend a night of innocent sleep with each other, with Cop 223 falling in love with the unnamed woman. In bridging the second story to the first, Cop 223 later bumps into Faye, a woman working at the Midnight Express, in a freeze frame and his voice-over remarks, " I know nothing about her.