Kamali lives with her sister, Malliga and brother-in-law, Shekar in Kotagiri, and is searching for a job and lives with high hopes of getting married soon. While visiting Madras, her purse is stolen and she fears she has lost her academic credentials. Suriya who is a orphan and care-free man, works in Jaipur finds the purse and sends it back to her, and a love develops through letters and phone calls. They agree to love each other without meeting, as she sews and sends a gift pack containing a lotus embroided woollen sweater for him to wear when they meet in real. As Suriya shifts to Madras for work and stays with Siva. Kamali too moves for Madras to find a job for her and stays with her friend Jensi. Suriya is attracted and smitten by his boss Neya. Her repeated attempts in gaining his love and affections fails as he staunch on his love for Kamali. In the meantime, unintentionally they both run over upon each other without knowing who they really were resulting in negative perception and misunderstanding. Refusing an Job offer which would move Kamali to Singapore, making it difficult for her to find Suriya she moves back to her home in despair. Unable to withstand the advances of Neya, Suriya quits the job gets sheltered by Paneer, who arranges him an autorickshaw to engaged as driver. Jeeva, a wealthy businessman expresses his interest in marrying Kamali to Shekar, but Kamali excuses herself to consider her as prospective bride when she meets Jeeva in private and shares her unflinching love for Suriya, who even allows her to meet him for one last time. Shekar, who initially dissuades Kamali's love finally gives in and allows her to Madras half-heartedly. Upon arriving in Madras, which is experiencing severe monsoon, Kamali finds that Jensi and other hostel mates were out of station. Pinning hopes, she boards the Suriya's autorickshaw, driven by him without knowing it him traces and searches for him desperately, wherever he lived. At the end of the day, both gets refreshed at his place, while he dons her gifted sweater covered by his uniform. As Kamali plans to head home, depressed, Suriya asssists her to board Nilgiri Express. As the train departs, in a turn of events, Suriya removes his shirt wherein Kamali notices it was her gifted sweater and finally unite, as Paneer and Jensi watches the pair and rejoices.
The basic theme of the film was inspired from "Puranaanooru" literature on the relationship between King Kopperum Chozhan and poet Pisirandhaiyar, though they never met but they developed a strong relationship until their deaths. Agathiyan confirmed this in his interviews. Agathiyan initially wanted to make his directorial debut with this subject since no producer were willing to produce the film, he made few films and earned his breakthrough with Vaanmathi. Post its success, he chose Ajith, actor from that film to play the leading role with Sivasakthi Pandian agreeing to produce the film. Agathiyan had asked Devayani to change her glamorous on screen image for the film, and Devayani duly agreed with the film becoming the start of several other similar roles for her. The film was initially titled as Nila Odi Vaa before it was named as Kadhal Kottai.
Soundtrack
The music was composed by Deva and lyrics written by Agathiyan and Ponniyin Selvan.
Reception
Tamil magazine Ananda Vikatan appreciated the film by giving 52 marks and mentioned that the basic plot was a novel idea which had been given a good shape and life by the filmmaker.
Novelization
The film was released as a novel in 2010 under the same name.
Kadhal Kottai is considered a cult film and a landmark in Tamil cinema diverging from traditional romantic films of the time This film has been included in the book written by Dhananjayan.G "Pride of Tamil cinema 1931-2013" which covers films that have earned national and international recognition. The author wrote "Kadhal Kottai is a trendsetting film which breathed new life into Tamil cinema and paved the way for revival of love themes in a big way." According to The Times of India the film hits the top list of romantic films made in Tamil cinema. The film also hit the list of top romantic films of Tamil magazines Ananda Vikatan and Dinamani. The film is considered one of the blockbuster films in the career of Ajith Kumar. S. R. Ashok Kumar of The Hindu asked Tamil directors to list their all-time favourite Tamil films, veteran director K. Balachander named Kadhal Kottai in his list. Suseenthiran also mentions his favourite film as Kadhal Kottai.
