The film uses its title as an allegory for a clash across three generations, pitting the old against the new while testing the loyalties of family, love, and duty. The tale frames the family saga through the lenses of Kal (yesterday) for the past, Aaj (today) for the present, and Kal (tomorrow) for the future, with each generation pulling in its own direction. Diwan Bahadur Kapoor, (Prithviraj Kapoor), is the patriarch whose long-held plan is to pair his grandson with Rukmani, the granddaughter of a longtime childhood friend. Yet his grandson, Rajesh R. Kapoor, Randhir Kapoor, is deeply in love with Monica “Mona,” who is played by Babita Kapoor in the cast, and he resists the arranged match.
Ram B. Kapoor, the father in this family constellation, is portrayed by Raj Kapoor. He watches the evolving dispute between his father and son with a growing sense of being torn, feeling the burden of the generations bearing down on him. Ram’s friend, Iftekhar, tries to help by suggesting a feigned detachment—a plan to stay in a hotel and appear to be drinking away the strain—to keep the peace, a ploy that buys time but cannot truly mend the rift.
Seeing neither side willing to yield, the grandfather and grandson attempt to “solve” the conflict by acting as if the issues have been settled. Ram, hoping for harmony, hosts a party in celebration, but the joyous mood shatters when he overhears the two men discussing the ruse, leaving him feeling betrayed and more isolated than before.
As Diwan Bahadur Kapoor falls ill, a poignant truth emerges: he longs to witness his grandson’s wedding and to feel the family united at last. This moment of vulnerability pushes Rajesh to a painful choice—he offers to sacrifice his own happiness for the sake of his grandfather’s peace. Mona, the woman he loves, agrees to the sacrifice and prepares to participate in the planned wedding. The ceremony, however, becomes a dramatic twist of fate when Rajesh marries a girl named Laxmi, only for the veil to be lifted and Mona to appear as the bride. Diwan Bahadur Kapoor consoles him, explaining that if Rajesh has given so much for him, he must also show a willingness to sacrifice for Rajesh.
In the final turning of the wheel, the elder generation’s sentiments soften, and the two generations begin to find a way forward—not through force, but through compromise and understanding. Rajesh honors his grandfather by scattering his ashes, a ritual that marks the end of an era and the fragile beginning of a new one. Not long after, Rajesh and Mona’s union is rewarded with the arrival of a son, bringing Ram the irreplaceable joy of becoming a grandfather at last, and sealing the film’s message about reconciliation, family bonds, and the enduring circle of generations.
