Ruby My Darling (remake of Tamil movie 'Kilinjalgal') is a deeply emotional romantic drama that portrays the innocence, intensity, and ultimate tragedy of young love. Set around the everyday world of college students and small-town families, the story follows Babu (played by Mohan) and Ruby (played by Poornima Jayaram), whose playful encounters on train journeys blossom into a sincere and passionate romance. Their love, however, is met with relentless resistance — from strict fathers, rigid social norms, and the ever-watchful eyes of their community.

As misunderstandings escalate and Ruby's family arranges a marriage against her will, the young lovers struggle to stay connected. Friends become mediators, fate intervenes cruelly, and desperate attempts to reunite only deepen the heartbreak. In a devastating climax, Ruby loses her life under the weight of emotional torment, and Babu, unable to bear the loss, dies beside her, choosing union in death when life would not permit it.