Gautham Menon announced in October 2013 that he would produce and direct a film featuring Silambarasan in the lead role. In an interview with Bangalore Mirror, Menon stated that the film was originally titled Sattendru Maarathu Vaanilai.
He described the film as one which starts as a "love story" and then enters a "violent / action space." Silambarasan supported this statement, saying that it will be in a similar genre to Menon's previous films Vettaiyaadu Vilayaadu and Yennai Arindhaal. Menon treated the romance differently wherein the hero is not really sure if he is in love but he is in a friendship that opens up gradually. Menon outlined the storyline of the film, stating, "This film is a feel-good love story and a story of friendship. It is the story of a happy-go-lucky guy (played by Silambarasan) who is looking to do normal things in life but then, a situation is thrown at him and it changes everything." The film story is inspired by the scene in the film The Godfather where a bruised Michael Corleone plots revenge against the corrupt policeman McCluskey. Menon has portrayed cops as heroes but the cop is the antagonist. When he was writing the second half of the film, he ensured not to watch films in the other genre. After he saw the film Angadi Theru, he could not write his film script for two weeks.
In December 2013, A. R. Rahman was officially confirmed to compose the songs. Dhilip Subbarayan was signed on as stunt choreographer. Though previously Marc Koninckx was reported to handle cinematography, Dan Macarthur was confirmed. Baba Sehgal was chosen to portray a negative role as a cop. By end December 2013, reports stated that Pallavi Sharda had signed a two film contract with Photon Kathaas and would feature as the lead female in the film. However, Menon clarified that it was not Pallavi Sharda, but another actress Pallavi Subhash. He conducted a screen test, auditions and a ten-day workshop before signing her for the film. However, Pallavi Subhash opted out because she had committed to a Hindi TV serial Chakravartin Ashoka Samrat and its dates were overlapping with the film. Later, she was replaced by Manjima Mohan.
Actor Vineeth Srinivasan made Menon watch the trailer of Oru Vadakkan Selfie and then Manjima was auditioned and selected for the role. On her role, she stated: "I play the character of someone, who visits her friend on vacation and meets this guy (character played by Silambarasan). It’s different from the role I played in Oru Vadakkan Selfie. In that, I had to underplay my character." Silambarasan's character in the film is about courage and inner strength.
