The plot revolves around Karthik and Shwetha, who are college mates from upper-middle-class families. While in college, they meet through some common friends and hang out often as a group. Shwetha has a childhood friend Genni, who is very protective of her and often wards off the boys who try to hit on Shwetha, and Karthik's friend Jai on the other hand encourages him to fall in love. Karthik falls in love with Shwetha eventually, but he hesitates to tell her. On Shwetha's birthday, Karthik intends to propose her but when he hesitates yet again, Jai lets the cat out of the bag, and tells that Karthik loves her, but Shwetha rejects the proposal. After a series of pursuing and some serious drama like falling from a moving bus, Shwetha agrees to Karthik's proposal.
Genni advises Shwetha to avoid Karthik, since Shwetha is equally interested in Karthik, she conceals all the proceedings from Genni. But Genni happens to find out about them, and she confronts and Shwetha seems to apologize, but after Genni finds that Shwetha has made Karthik to overhear their girl talk through her mobile, she splits up from Shwetha and complains to Shwetha's mom that she is going out with some guy. Shwetha tackles her mom by blaming that she avoided Genni because is rotten in mind and is jealous. So to seek revenge, she must be doing this on purpose. Her mom gets suspicious but still believes Shwetha's side of the story.
Karthik and Shwetha continue to see each other. Soon one thing leads to another and they get intimate during overnight trips and outings. Within two months, Shwetha finds that she has missed her period, coincidentally her mom asks why she has not used her sanitary napkins and there are so many left overs. She manages the situation by telling that she used the pads from her friend's house when she stayed there.
Shwetha confides in Karthik and few other friends that she might be pregnant and they ask her to perform a self pregnancy test which turns out to be positive. So they go to some unknown place to abort the foetus posing as a married couple. But the doctor gets suspicious when they answer irrelevantly and chucks them out. They find another person who does the abortion through a hostel warden and learn that this new place is pretty expensive. Karthik, Shwetha, Jai and other friends try to arrange for money and finally on the day the abortion is supposed to be done, Shwetha vomits in front of her mother at her house. When her mom insists that they go to a doctor to check for food poisoning, Shwetha becomes restless and shouts at her. Her mom relates the unused pads and her vomiting and her behavior and realizes that she is pregnant and then all hell breaks loose.
Shwetha's dad speaks to Karthik's dad along with few relatives, and they argue. Shwetha's family, being on the receiving end want to finish the problem by getting them married. But Karthik's dad is not interested since his reputation will be spoiled. So, the lovers plan to elope and while they are on the way, Shwetha changes her mind and tells that her parents will feel bad. Karthik on the other hand tells that his parents will not agree for them to be together. They argue a lot and that forms a rift between them, but still they choose to stay together and return home. The families continue to argue about the marriage, and then finally Karthik's parents agree, provided Shwetha aborts the baby. But she refuses telling that the sole evidence will be lost and then again Karthik's parents will not get them married. Karthik tries to convince her, but it only leads to another argument and Shwetha walks off leaving an irate Karthik behind.
The parents also argue about the marriage and when some relatives speak ill about Shwetha and her character, (that she has acted like a prostitute and so she must take money for her services and not ask for marriage) Shwetha's father gets insulted and he leaves the place in tears. When Shwetha's mom knows this, she fights with Karthik's parents in front of their house, but Karthik has now changed his mind about marrying Shwetha because of the previous argument and he doesn't care anymore and is selfish and stone faced even when her whole family is in tears in front of his house. That is when Shwetha too decides that she doesn't want to be with Karthik anymore. And they leave his place.
Finally,a few months later a baby boy is born and Shwetha's dad leaves him in an orphanage. Two years later, we find that Shwetha is happily getting engaged to someone else, while Karthik is busy in a coffee shop flirting with another girl and the little child grows up in the orphanage without parental love and care.Santhosh Ramesh as Karthik
Manisha Yadav as Shwetha
Jayaprakash as Shweta's father
Thulasi as Shweta's mother
Poornima Jayaram as Karthi's mother
Ramnath Shetty as Karthi's father
Arjunan as Jai
Archana Raja as Genelia
Durga as Karthik's sister
After Rajapattai, which was based on a script by a friend, Suseenthiran went back to new scripts and chose Aadhalaal Kadhal Seiveer. "This is a story that has never been explored before in Tamil cinema. You cannot classify this film as mainstream. The enormous impact of the script will be felt in the film’s second half", he said. Santhosh, a third year Loyola College student, plays the hero, while Manisha Yadav, who played one of the leads in the critically acclaimed Vazhakku Enn 18/9, the heroine. Some students from both Loyola and MOP Vaishnav colleges have acted in the film. Actor Poornima Bhagyaraj makes a comeback with this film. Apart from her, actors Jayaprakash, Thulasi and Arjun, who played a commendable role in Kadhalil Sodhapuvadhu Eppadi, are the other three familiar faces in the cast. The rest are newcomers. For the film all artistes attended a two-month rehearsal.
Suseenthiran came up with the script of Aadhalal Kadhal Seiveer while chatting with a friend who was talking about one of his relatives, a college girl, who had fallen in love. "As he discussed her story, several issues one would normally not associate with a couple in love emerged. The impact was such that I was prompted to make a movie out of the story," says Suseenthiran. Suseenthiran has convinced the young music director Yuvan Shankar Raja to appear in a music video for a song from the film. Unlike most other films, this film’s title will not be showcased at the beginning but at the end.
The soundtrack of the film was composed by Yuvan Shankar Raja. There are six songs but only four will be featured in the album as the director feels that the lyrics of the other two songs would give out the plot details. These two songs will only be a part of the film. The audio launch was held on 17 October at Sathyam Cinemas, Chennai. The first audio CD was released by actor Mohan and received by director-actor K. Bhagyaraj.
The music was praised by critics. Behindwoods wrote, "Yuvan Shankar Raja proves why he is the ‘Little Maestro’ in the finale of the movie and the little pathos song sung by Yuvan himself, will surely move you". The Hindu wrote, "topping the list of other highlights is Yuvan Shankar Raja’s score. The songs have been chartbusters for quite a while. Now you notice his RR beautifully enhancing the mood of the sequences". The New Indian Express wrote, "Yuvan Shankar Raja’s background score is a key strength to the film". Rediff wrote, "music by Yuvan Shankar Raja is melodious and pleasing to the ear, particularly the Poovum Poovum number by Vijay Yesudas and Vinaitha". Sify wrote, "Yuvan Shankar Raja’s music is peppy and the pathos song sung by the music director in the climax and picturised on the child artist is heart-warming and will move you to tears".
It was released by Udhayanidhi Stalin's Red Giant Movies though Studio Green had initially acquired the distribution rights of the film. The satellite rights of the film were sold to STAR Vijay. The film was given a "U" certificate by the Indian Censor Board. The film which supposed to hit screens on 23 August 2013 was advanced to 15 August, on Independence day.
Suganth of The Times of India gave 3.5 stars out of 5 and called Aadhalal Kadhal Seiveer, "a return to form for the director after the misfire that was Rajapattai. Malini Mannath of The New Indian Express wrote, "Aadhalal Kadhal Seiveer comes as a breath of fresh air. Clear and focused in its screenplay, it is sensitive in handling the issue of premarital sex and teen pregnancy. Brilliantly narrated by Suseenthiran, it capsules a relevant issue in just 106 minutes. Aadhalal Kadhal Seiveer is an experience not to be missed". Sify wrote, "Suseenthiran is back in form with his latest realistic Aadhalal Kadhal Seiveer. He has come out with a different kind of film which is sure to pull at your heartstrings and at the same time make you think of the realities of life". S Saraswathi of Rediff gave 3 stars out of 5 and wrote "Aadhalaal Kaadhal Seiveer is a must watch. A simple and honest screenplay with a liberal dose of realism coupled with some excellent editing, but most of all, the totally unexpected climax, sets this film apart". Malathi Rangarajan of The Hindu wrote, "Nearly two years after Rajapaatai, Suseenthiran bounces back with AKS that has a neatly told story and a finale that touches an interesting emotional acme". Indo-Asian News Service wrote, "Suseenthiran handles the film bravely without compromising on the message it sets out to deliver to its audiences. Any story dealing with a social problem is either extremely preachy or overtly melodramatic, but what we get here is an intelligent output sans cliches. Kudos to the director for writing and narrating an impactful story". Behindwoods wrote, "AKS is a ‘slice of life’ tale topped by a really impactful climax. Suseenthiran is back in form with a short impactful teenage romance".