Across a college in Ooty, Sreenath Prasad aka 'Seenu' (Varun Dhawan) fails his final exam by two marks. Eager to get a degree, he kidnaps the professor's daughter during her wedding and demands his professor to give him two more marks in exchange for his daughter. Seenu accidentally lets go of her however while letting his parents in to his house, and his plan fails.
Although Seenu's father offers him a job at his auto stand, Seen plans to get a degree at Tift College in Bengaluru. He leaves Ooty on a train headed for Bengaluru. On the train, he beats up a gang harming a group of teenage girls. When Seenu arrives in Bengaluru, a friend of his who lives there reluctantly allows him to stay in his house.
Once Seenu arrives in Tift College, he prays to Krishna (Salman Khan's voice) to concentrate on nothing but studies. However once he finishes, he sees a girl named Sunaina (Ileana D'Cruz) and gets attracted to her. He tries to get her attention, but she ignores him constantly. She tells him that she has been forced into marrying a corrupt policeman named Angad Negi (Arunoday Singh) since he tricked her father into shooting Angad's sidekick and friend Peter's (Rajpal Yadav)arm. Angad's men chase Seenu until he beats up two of them and scares away the rest. Seenu goes to Angad to make a truce with him and leave Sunaina, but Angad (believing he cannot do it) gives Seenu a chance to try to woo Sunaina for up to three days. Seenu publicly tells Sunaina he loves her and tells her not to be afraid of Angad and his goons. She gains courage, scares off Angad's men, and falls in love with Seenu. Angad finds Seenu, finds out what happened, and attempts to shoot Seenu, but instead accidentally shoots Peter. The media quickly finds out and Angad gets suspended as a police officer.
All seems well until Sunaina is kidnapped and taken away in a helicopter. Seenu learns from Angad that Sunaina will be taken to the mansion of Vikrant Singhal (Anupam Kher), one of Asia's most notorious gangsters. Vikrant's daughter, Ayesha (Nargis Fakhri), was on the Ooty to Bangalore train Seenu was in and was attracted by his impressive fighting skills. She told her father about the experience as well as her interest in marrying him. Angad and Peter told Vikrant's men that in order to get Seenu, they would have to take Sunaina to lure him to their place, forcing Seenu to marry Ayesha.
In the second half of the film, Seenu goes to Vikrant's residence in Bangkok, Thailand. He tricks Vikrant and his friend and associate Balli (Saurabh Shukla) into thinking that he wants to marry Ayesha. However, he requests that he is given ten days to get to know Ayesha before the wedding day, which Vikrant initially refuses until Ayesha tells her father to "do as Seenu says". Ayesha lets Sunaina wear any of her clothes because she has an "extra piece" for all of her clothing. Ayesha and Seenu spend the day together; later, Seenu tells Ayesha that she does not love him. When Angad and Peter come later, she then falls in love with Angad through a sheer coincidence.
Seenu and Sunaina use Ayesha's love for Angad as a way of solving their problem. Sunaina wears identical clothes to Ayesha; in result, Angad confuses Sunaina for Ayesha, making Ayesha believe that Angad loves her. The plan later fails, though, when Angad realizes this and tricks Ayesha once again into marrying Seenu. Angad is tricked by Seenu and Sunaina into kissing Ayesha, but Vikrant sees this and points his gun at Angad to shoot him, but Ayesha steps in between and stops him saying that she loves Angad. Seeing this, Angad realizes that Ayesha's love for him is true and that Ayesha is the right girl for him, not Sunaina and decides to marry Ayesha. Vikrant realizes his daughter loves Angad and reluctantly tells Seenu that Ayesha will marry Angad. Seenu pretends to be agonized but celebrates later. Ayesha marries Angad, and Vikrant convinces Sunaina (who is also pretending to hate Seenu) to marry Seenu, by saying that he took 10 days to hatch a plan to bring Ayesha and Angad together, not to get to know Ayesha (not realizing that this is true!) Seenu and Sunaina are back together again.