Development After being impressed by director
M. Rajesh's debut film,
Siva Manasula Sakthi (2009), producer
Udhayanidhi Stalin of
Red Giant Movies wanted to act in the director's next film but was informed that he was already directing
Boss Engira Bhaskaran (2010). Udhayanidhi ended up buying that film's distribution rights. After he met Rajesh, both decided to collaborate on a new project. Rajesh suggested the title
Sumarana Paiyyanum Super Figurum (), which Udhayanidhi rejected. Despite reports that the film was titled
Nanbenda (), it was later revealed to be
Oru Kal Oru Kannadi (OKOK), after a song from
Siva Manasula Sakthi. Cinematography was handled by
Balasubramaniem, editing by
Vivek Harshan, and dance choreography by
Dinesh. Rajesh said, "I have shown mistakes committed by both genders in
Oru Kal Oru Kannadi . Having said that, I must admit that in real life, most men I know are at fault when it comes to relationships".
Casting Though Udhayanidhi made a cameo in
Aadhavan (2009),
Oru Kal Oru Kannadi is his first proper acting credit. To prepare for his role, he observed
Jiiva's mannerisms in
Siva Manasula Sakthi. Rajesh cast
Hansika Motwani as the lead actress after being impressed with her performance in
Engeyum Kadhal (2011). Motwani, a non-Tamil speaker, learned the language at Rajesh's request. Comedian
Santhanam renewed his association with Rajesh for the third time. Rajesh noted that while the character of Partha was merely created during scripting, it was only after Santhanam's casting that the character was fleshed out after the actor and director
brainstormed. Santhanam revealed that the character's mannerisms were inspired by one of his friends.
Saranya Ponvannan, who plays Udhayanidhi's mother, said that since the film was a comedy, she was insecure and doubted she could meet the pace of Santhanam and Rajesh who specialise in that genre, despite herself having tried comedy in
Em Magan (2005) and
Kalavani (2010).
Narayan Lucky briefly appears as a potential suitor for Motwani's character who ends up ridiculing her. He said Rajesh initially considered
Arya or Jiiva for the role, but later decided on Narayan as he wanted to give the scene a "fresh feel". Arya, who made a cameo in
Siva Manasula Sakthi and starred in
Boss Engira Bhaskaran, made a cameo near the climax, and joked that he was Rajesh's "lucky mascot".
Sneha was cast in another cameo, which was reportedly offered to
Tamannaah Bhatia, and
Andrea Jeremiah reportedly received for her cameo. Vibhu, who later gained fame for the TV series
Ethirneechal, appears briefly as Motwani's groom.
Filming A photo shoot featuring Motwani and Udhayanidhi was conducted in February 2011, while
principal photography began in mid-March at Chennai. Prior to this, the team conducted rehearsals with Udhayanidhi; Rajesh said, "[Udhayanidhi] acted like a pro. We shot all the scenes on a
handycam and were impressed with his performance. He is now clear about his dialogues". The first scene was shot in
Madhava Perumal temple, Mylapore. Rajesh shot some scenes at
Sathyam Cinemas in Chennai due to his affinity for the theatre, having previously filmed a scene there for
Siva Manasula Sakthi. By mid-May 2011, the team had completed two schedules of filming, which took place mostly in real locations across Chennai, rather than sets. In June, the team travelled to
Madurai for filming a major sequence. Rajesh revealed that though Motwani lost some weight for her role, she later gained additional weight before production could be completed, leading to the inclusion of
self-deprecating dialogues about her increased weight. The team returned to Chennai for filming the climax sequence, held at a resort in
East Coast Road. During this schedule, shooting was interrupted due to Chennai-based technician union members' objection to using a
Mumbai-based makeup artist for Jeremiah. Udhayanidhi then intervened and asked the makeup artist to leave the set, resulting in the shooting being delayed. The final schedule was held at Mumbai in mid-July 2011; though this coincided with the
Mumbai bombings, Rajesh
tweeted that they shot at a suburb which was away from the city. By August, the team shot few patchwork sequences and spoken portions at the
Tharamani–OMR stretch. Since they were denied permission to shoot on road because it would obstruct traffic, they shot at
Rajiv Gandhi Salai. By October, filming was mostly complete, except for a few sequences set to be canned in overseas locations. That December, the makers travelled to Jordan to shoot a song sequence. Another song sequence was shot in Dubai. By February 2012, filming was mostly complete except for a remaining song sequence. == Soundtrack ==