<p>Letter writing in cinema is one of the oldest, thriving, and familiar narrative devices that signify the emotional expression of characters. As one of the most employed literary devices in cinema, letters create emotional depth in the narration while serving various symbolic functions. Existing academic contributions reveals that cinema has been studied at various levels with respect to its narratives. Letters, which has been employed from the early days of cinema to present remains underexplored and demands more academic attention. This systematic review, guided by PRISMA, critically identifies the gap in existing literature on the representation of letters in contemporary films, revealing that New Wave Malayalam cinema remains relatively underexamined. The New Wave Malayalam cinema, beginning from 2010, employs unique storytelling techniques to explore complex human emotions and relationships. Realism and social themes often portrayed in Malayalam cinema resonate with the audience. These tools are vital in shaping plots, characters, and the overall story structure of a film. The review points out the cinematic functions of letters, emphasising the representation and construction of emotions through letters. In the light of Sustainable Development Goal 3(SDG3), the survey highlights how films employ literary devices like letters as a tool to construct emotions while preserving its aesthetic values.</p>