When an honest cop, Vijay Kumar's family is ruthlessly slaughtered by a politician and his aides, he decides to change his identity and commits his life to bring his daughter up in a serene atmosphere. But some freak events end up compromising his identity and what he does to save his daughter and avenge the death of his family unfurls as Theri.
John (Arya) and Regina (Nayanthara) are forced into wedlock against their wishes. Both undergo a rough patch initially in their marriage as they are not able to get over their past romances. Prior to their marriage, Regina was in love with Surya (Jai), while John romanced Keerthana (Nazriya). What leads to the Arya-Nayanthara wedding? How they forget their romantic past and finally come together forms the rest of the story.