Kundavi was brought up in a small village called Ambasamudram. She, along with her two friends, decide to have a love marriage. However she is not so successful. Her father arranges her marriage to Gowtham against her wishes. Both look gloomy during the wedding due to obvious reasons. Six years later in Mumbai they have a five-year-old daughter Ishwarya and live as a happily married couple. Gowtham works as the chief mechanic at Maruti Suzuki and Kundavi works at a local call center. Gowtham goes to New York City for a short period. During this time, Kundavi comes across Gowtham's old college diary. Gowtham wanted to be an engineer from a young age and forced his father's brother to pay for a seat in Coimbatore for mechanical engineering. From the second year of college he is the don. In college, he is attracted to Ishwarya, whose father is a Coimbatore MP. Gowtham and Ishwarya fall in love and decide to get married. At the registrar's office after Gowtham ties the knot, Ishwarya's father and his men beat him up, separating the lovers and sending Ishwarya off to Sydney, Australia. At the end of the diary, Gowtham writes a note: "If I have one wish, it would be to live with Ishwarya happily at least for one day." Gowtham returns from New York and finds his wife changed. She works late and avoids him. She finds Gowtham's lost love Ishwarya, who had just returned from Australia. Ishwarya has become a modern girl in contrast to the demure salwar kameez girl she was in college. Kundavi asks Ishwarya to visit them and she tells her husband that he should live happily with Ishwarya for a day and that for that one day, she and their daughter do not exist for him, and leaves Gowtham with Ishwarya. That day Gowtham spends with Ishwarya, Kundavi imagines them to have a good time and eventually fall in love with each other all over again. When she gets back home, dreading, she finds her husband alone at home. She asks about his day with Ishwarya, and he gives her a letter written to Kundavi from Ishwarya. In it, Ishwarya says that within five minutes of speaking to him, Gowtham mentioned 'Kundavi' so many times that she realised that he loved his wife very much and is leading a very happy life. She wishes the couple a happy life and leaves, never to return. In the end, Gowtham confesses that he has hidden the secret of loving someone so that Kundavi doesn't get hurt as any girl would not bear her husband's love being shared. However, unlike others, Kundavi has brought the girl her husband loved in order to make him happy. They then cry in happiness and hug each other while Diwali fireworks blossom. Their daughter Ishu also joins them at the end, and the film ends with a happy family celebrating Diwali.
Reports emerged in August 2005 that Suriya and Jyothika would come together for a project titled Jillendru Oru Kadhal based on a real life story newcomer N.Krishna would direct it. The team signed up A. R. Rahman to compose the film's music while Asin was selected for another key role in the film after her successful pairing with Suriya in Ghajini. However, by the time the film was launched in December 2005, Bhumika Chawla had replaced Asin. The film was shot extensively in Rajamahendravaram, Visakhapatnam, with some portions in Mumbai, Coimbatore and Chennai, while a song was shot in Switzerland masquerading it as New York. Initially touted as an August 2006 release, the film was delayed to avoid a clash with Jyothika's other film Vettaiyaadu Vilaiyaadu.
Soundtrack
The film features a soundtrack composed by A. R. Rahman. The music for the film was released on 2 August 2006 by K. M. Musiq and a day later in India by Star Music. Shreya Ghoshal won the Tamil Nadu State Film Awards and Filmfare Awards South for Best Female Playback Singer for the rendition of the song Munbe Vaa.
The satellite rights of the film were sold to Kalaignar TV. The film was censored on 4 September 2006 and was given with a "U/A" certificate, with some dialogue muting. The film opened across 207 screens worldwide on 8 September 2006, three days before the wedding of the lead pair Suriya and Jyothika. The film received a large opening, and became a superhit at boxoffice . Critics primarily labelled the film as a disappointment as a result of the high levels of publicity it received prior to release. The Hindu gave the film a negative review, claiming that "The most talked about movie of the year, Studio Green's Sillunu Oru Kadhal featuring Suriya and Jyotika, arrives only to disappoint", further stating, "it lacks a strong cohesive script to bind the elements". The film was later dubbed and released in Telugu as Nuvvu Nennu Prema. In 2017, the film was dubbed into Hindi as Mohabbat Ke Dushman by Goldmines Telefilms Pvt. Ltd.
