Chitra Nayanthara is a medical student who, with a small group of friends, is engrossed in a neuroscience project about the human brain. She becomes intrigued by the case of Sanjay Ramaswami Suriya, a wealthy Chennai-based businessman said to suffer from anterograde amnesia. When her professor Ravindran denies access to Sanjay’s records because the case is under criminal investigation, Chitra decides to pursue the mystery in secret, piecing together clues that others overlook.
Sanjay experiences memory gaps every fifteen minutes, rebuilding his life with a meticulous system of photographs, notes, and tattoos that help him recover after each cycle. This isn’t random wanderlust; it’s a carefully choreographed vigil of memory. He is ultimately driven by a personal goal: to avenge the death of his lover, Kalpana Asin Thottumkal, targeting the people responsible. At the center of his hunt is Lakshman, the head of a Kolkata-based human-trafficking network and a prominent social figure in Chennai, whose shadowy influence extends into many lives. On the case, Inspector Ravi Riyaz Khan follows the pattern of brutal killings, hoping to untangle the truth behind the missing memories and the crimes.
In 2002, Sanjay, the owner of the AirVoice mobile company, meets Kalpana [Asin Thottumkal], a struggling advertisement model, and the pair quickly develop feelings for each other as he presents himself to her as “Sanjay Manohar.” They grow closer, and the diary entries reveal a tentative proposal that Kalpana accepts on one condition: she would marry only after she fulfills a past commitment. The diary ends on this note as Sanjay leaves for a business trip, and their romance seems to pivot on secrets yet to be revealed.
As the investigation unfolds, Ravi tracks Sanjay to his flat, where a confrontation ends with Sanjay being knocked unconscious and the two diaries—marked 2002 and 2003—being discovered. Chitra secretly reads the 2003 diary and learns that Kalpana’s life took a dramatic and deadly turn. The truth emerges: Kalpana traveled to Mumbai to rescue 25 innocent Tamil girls trafficked to Mumbai and Kolkata, a mission that triggered Lakshman’s wrath. In a brutal counterstrike, Lakshman’s goons killed Kalpana with an iron rod when she confronted the linked violence.
With this new knowledge, Chitra confronts Sanjay and urges him to direct his rage toward Lakshman. Lakshman’s twin brother Ram [Pradeep Ram Singh Rawat] also arrives from Kolkata to aid the pursuit. The pursuit leads to Lakshman’s factory in downtown Chennai, where Sanjay, Ram, and their henchmen clash in a tense showdown. Chitra alerts Sanjay to the unfolding danger at the dormitory, and the ensuing struggle sees Sanjay fighting off Lakshman and Ram, fueled by the memory of Kalpana. In a climactic turn, Sanjay finally overpowers the brothers, his vengeance fulfilled.
The story closes on a heartfelt note: Sanjay leaves with Chitra, pausing at a crossing to allow the children to cross. A young girl smiles at him, and he returns the smile, a quiet, hopeful moment that crowns his long, painful journey toward memory, justice, and a fragile peace.
