Ordinary housewife Inyeong meets carpenter Huisu by chance in a café and for fun they decide to become coffee mates: friends who only meet in cafés and nowhere else. Although they don’t make calls or send texts, they can talk to each other about anything while sitting in a café. They share everything, from their daily routines to their deepest secrets, which have never been shared with anyone before. The coffee mates thing started out as a kind of joke but in the end, it shatters the two people’s entire lives, leaving them to face an awful truth they had never been aware of. Movies tackling the subjects of amorous passion and infidelity most often focus on the sexual desires therein; an accidental encounter leads to sexual indulgence in each other, typically resulting in a ruined relationship, one way or another. Coffee Mate overturns this convention, as it is the mental rapport and not the physical union of the sexes that makes their regular married lives impossible to maintain.