The movie begins with Chandu (Siddharth) and Siri (Shruti Haasan) as childhood friends. Chandu and Siri call each other "Faltoos" and "Killer", respectively, affectionately. Their friendship remains intact even as they grow up. Chandu who was sent to Mumbai to do MBA, instead learns music and returns home which leads to agony of his father. However, Siri convinces Chandu's father that it is her responsibility to take care of Chandu's career. They go for an audition where they get into a fight with a band and he is sent out of the audition. Prior to that, Siri accepts love proposal by Uday (Navdeep), who lives in US after consulting Chandu. Later, Chandu and Siri accidentally meet their common friend in college, Ritu Sharma (Hansika Motwani) and Chandu falls in love with her at first sight. Chandu starts spending time with Ritu to impress her, but Siri feels that she is being avoided. Siri decides to leave for a dancing School at Chennai. Meanwhile, Ritu accepts Chandu's love proposal. When Siri is about to leave, Chandu apologises her that he had not noticed that she was being avoided. At the same time, Uday comes back from US to surprise her. Hence, she decides not to leave.
Chandu decides to attend Airtel music competition in Kochi as a lead guitarist in a band. Siri, Uday and Ritu accompany him to Kochi. They all stay in a hotel in Kochi, where Clarity Kanna Rao (Ali) is the servant. Chandu gets his practice through the band where he fought already but later on they become friends. Chandu wins the competition with guitar gifted by Siri. However, the events in Kochi displaying deep friendship between Chandu and Siri attracts jealousy of both Ritu and Uday. Finally, Uday calls for break up by asking to decide between him and Chandu. Chandu's father defends Uday's opinion and asks Chandu and Siri to realise their love. But, Chandu insists that their friendship can't be turned into love and tells Uday to marry Siri, promising him that he will not be in touch, see her and talk to her for ever. The movie ends with Siri giving birth to Uday's child, while Chandu and Ritu, now a married couple, come to see them at the hospital.
At the hospital, Uday realizes his mistake of separating them and asks Chandu and Siri to become friends again. They both reunite as Ritu enters now as Chandu's wife and feels happy for them. The four friends leave with Siri and Uday's baby in Chandu's car, now becoming best friends forever.
Cast[edit]
- Siddharth as Chandu "Faltoos"
- Hansika Motwani as Ritu Sharma
- Shruti Haasan as Siri Chandana "Killer"
- Navdeep as Uday (in an extended cameo appearance)
- Tanikella Bharani as Chandu's father
- Lakshmi Ramakrishnan as Chandu's mother
- Vinaya Prasad as Siri's mother
- Ali as Clarity Kanna Rao