Kung (Eric Tsang) and Kin (Jacky Cheung) have been rivals since the 1970s, when they both vied for the affection of the same woman, who ultimately married Kung (Anita Yuen). Today, they own rival phone shops situated directly opposite each other on the bustling streets of Mongkok, constantly devising outrageous promotions to outshine one another. In this fiercely competitive environment, fraternizing with the opposition is unheard of—until their children unexpectedly fall in love. The situation becomes even more chaotic when the landlord decides to triple the rent for all the shopkeepers, aiming to evict them for redevelopment purposes.