anucharan, a director of several short films, music videos and television shows in australia, had come to chennai for his sister's wedding, when m. manikandan, the director of "kaaka muttai" and a close friend of him, and composer g. v. prakash kumar, encouraged him to make a tamil film, after hearing the script of "kirumi". manikandan introduced anucharan to jayaraman, a former assistant, who had worked with actor rajinikanth for 24 years and who decided to produce the venture along with his friends prithiviraj and rajendran as he liked the script since it was "contemporary" and had a message for society. following g. v. prakash kumar's suggestion, kathir was cast as the protagonist of "kirumi", who had also been part of prakash kumar's debut production "madha yaanai koottam". despite the film being titled "kirumi" (eng. "virus"), kathir said that the film would not deal with a virus or natural disasters but that it was a "realistic film that deals with the life of an ordinary youngster and how certain incidents change his course of life", while its director anucharan added that the film had elements of a psychological thriller. he further informed that it was based on something he saw when he "was roaming on the streets of chennai".