'Naan Mahaan Alla' is a tale of two halves; the first half is a upbeat, jolly, playful love story that transforms into a raw, disturbingly violent tale of death and destruction in the second half.
Jeeva (Karthi) is a happy-go-lucky young man looking for a job, not that he is serious about it. He is a fun loving young man, always exuding positivity and is naturally popular in his circle. He has a doting family; dad (Jayaprakash) a call taxi driver, a house wife mother (Lakshmi Ramakrishnan), and a younger sister. Jeeva’s life revolves around his family and friends.
He meets Priya (Kajal Agarwal) at his friend Sudha’s (Neelima) wedding and falls for her. He expresses himself to her in an interesting manner and woos her in his characteristic playful and jovial manner.
When he seeks Priya’s hand in marriage, her father (Ravi Prakash) does not approve of this and averts to a local gangster to dissuade Jeeva. The ensuing events are the most unexpected ones for Priya’s dad as all hell breaks loose. When life seems be going on a straight track for Jeeva, it comes to a shrieking halt in the form of his dad’s scripted accident; and the unhappy turn of events from that point lead and culminate in a riveting climax.