Kaathu Vaakula Rendu Kaadhal

After the success of Naanum Rowdy Dhaan, Vignesh Shivan had planned a triangular romantic film starring Sivakarthikeyan in the lead role, with actresses Trisha and Nayanthara were under consideration for the female leads.[3] Later in 2016, Vignesh had announced Vijay Sethupathi playing the lead role in his film titled as Kaathu Vaakula Rendu Kaadhal; Anirudh Ravichander was reported to score the music which marked both Vijay and Anirudh's second collaboration with Vignesh after Naanum Rowdy Dhaan.[4] Produced by A. M. Rathnam, the shooting of the film was supposed to go on floors in August 2016, until Vignesh decided to remake the 2013 Hindi film Special 26 for his new project, the Suriya-starrer Thaanaa Serndha Koottam (2018)[5] and also to work with Sivakarthikeyan under a new project produced by Lyca Productions, which came under the tentative title #SK17.[6]

With #SK17 becoming shelved,[7] Vignesh decided to revisit the script with the same cast and crew members, whereas Trisha Krishnan walked out of the project citing schedule conflicts and was replaced by Samantha.[8] During the occasion of Valentine's Day (14 February 2020), Vignesh announced the film officially under the same title Kaathu Vaakula Rendu Kaadhal,[9] reporting that he will produce the film under his own banner Rowdy Pictures along with Lalit Kumar of Seven Screen Studios.[10] Nayanthara and Samantha were officially announced as the female leads, which is touted to be a love triangle story.[11][12] The film marked the debut of Shweta Sabu Cyril (daughter of veteran art director Sabu Cyril), who joined the film's team as the production designer.[13]

The shooting of the film was supposed to take place in April 2020, but was delayed due to the COVID-19 pandemic lockdown. In May 2020, the production house announced that the film will go on floors from August 2020.[14] On 10 December 2020, the team officially kickstarted the film on floors in Chennai,[15][16][17][18] with principal photography began from 14 December followed by Vijay Sethupathi's arrival in Hyderabad.[19][20] After the film's first schedule being completed, Samantha Akkineni officially joined the film's sets from January 2021 in Chennai as a part of their second schedule.[21] On 10 February 2021, Vignesh announced that the shooting of the second schedule being wrapped.[21] Vignesh Shivan announced through his Instagram on 21 March 2021 (World Down Syndrome Day), that Bhargav, who is affected by down syndrome, will be joining the team as one of the pivotal cast.[22] Though the filming was delayed due to the second wave of COVID-19, the film's shooting resumed in Pondicherry in August 2021.[23] On 23 August 2021, a video from the shooting spot was surfaced into the internet. It had the lead actors recreating the song "Valai Osai" from Sathyaa (1988), where the actors also wore costumes similar to that song.[24]

The satellite rights and digital rights were acquired by Star Vijay and Disney+Hotstar.