After the average response of his debut film Samurai (2002), Balaji was supposed to direct again Vikram in a new venture which however got shelved.
During the shoot of Anniyan (2005), Balaji narrated the plot of Kaadhal to his mentor Shankar who agreed to produce the film after hearing the script.
The film was initially turned down by actors Dhanush and Shanthanu Bhagyaraj, before Balaji Sakthivel consulted Shankar's advice for the lead role.
Telugu actor Ram Pothineni also auditioned for the lead role
After considering both Manikandan (Boys-fame) and Bharath, Shankar chose the latter to star in his production.
Saranya Nag (extreme right), who later starred in Peraanmai, was in Class IX, when cinematographer Vijay Milton referred her on to Balaji Sakthivel who subsequently cast her in Kaadhal.
Saranya was initially considered to play the heroine in the film, but the role was later handed to Sandhya, after the director felt she looked too young.
Saranya Nag thus made her debut in a supporting role in the film as Sandhya's friend.
Balaji Sakthivel's first choice for the lead role was Ileana D'Cruz. Since, she couldn't spare her dates, he opted for a newcomer.
Dhandapani from Madurai was selected to play Sandhya's father. He became popular with this film and adopted the film's title as Kaadhal Dhandapani.
Though the story was shown to have taken place in Madurai, shooting was done in Dindigul and Madurai.
The school where Sandhya studies is St.Joseph's Girls Higher Secondary School Dindigul.
The school authorities at first approved of the use of their school name in the movie without hearing the story.
However, the school authorities, after watching the final cut, demanded their name to be removed as the film, which was about two lovers eloping, claims that it is a true story.
According to Balaji, the movie is (with names changed) inspired by a real-life incident he heard during one of his train travels. But he did not produce any evidence for his claim.
The film has eight songs composed by Joshua Sridhar.
All lyrics are written by Na. Muthukumar.
Produced on a budget of 1.25 crores, Kaadhal was a surprise blockbuster, recovering almost its entire budget from Chennai distribution territory alone.
Upon release, the film was dubbed into Telugu as Premisthe.
It was remade in Kannada as Cheluvina Chittara (2007), in Bengali as Chirodini Tumi Je Amar (2008), in Marathi as Ved Laavi Jeeva (2010), in Nepali as Manjari (2013) & in Punjabi as Ramta Jogi (2015).
Here are a few nostalgic snapshots from the film...