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.
After the success of Kadhal Kondein (2003), Balu Mahendra partnered with Dhanush for his next film in July 2003. Initially, the director revealed that Adhu Oru Kana Kaalam would serve as a sequel to his 1979 film Azhiyadha Kolangal, with Dhanush playing a teenager smitten with a woman fifteen years his senior, played by Ramya Krishnan.