Following the success of Kadhal Kondein (2003), Balu Mahendra signed on Dhanush to appear in his next film in July 2003. Initially the director revealed that the film titled Adhu Oru Kana Kaalam would be an extension to his 1979 film Azhiyadha Kolangal stating that Dhanush would play a teenager infatuated by a woman who is fifteen years older than him to be played by Ramya Krishnan.
This followed the success of Kadhal Kondein (2003), and Balu Mahendra collaborated with Dhanush for his next film in July 2003. Initially, the director announced that Adhu Oru Kana Kaalam would be a continuation of his 1979 film Azhiyadha Kolangal, with Dhanush playing a teenager captivated by a woman fifteen years older than him to be portrayed by Ramya Krishnan.