| Director | Saran |
|---|
Rajaraman, nicknamed "Vasool Raja," is a local don in Chennai who makes a living by extorting money from people with the help of his right-hand man, Vatti. Given that his father, Sriman Venkataraman, had wished for him to be a doctor, he creates the faux Venkataraman Charitable Hospital, and pretends to live in accordance with this wish.
One year later, Raja's plan goes awry when Venkataraman meets an old acquaintance, Dr. Vishwanathan. The two men decide to get Raja married to Vishwanathan's daughter, Dr. Janaki, aka "Paapu." At this point, the truth about Raja is revealed. Vishwanathan insults Raja's parents and ridicules them for being ignorant of Raja's real life. Venkataraman and Kasturi, who are both aghast and heartbroken, disown Raja and leave for their village. Raja decides that the only way to redeem himself and gain revenge for the humiliation suffered by his father is to become a real doctor. He goes to a medical college to obtain an MBBS degree.
With the help of Vatti and others, Raja gains admission to the SLR Institute of Medical Sciences. Upon admission, he again encounters Vishwanathan, who is the college dean. His success there becomes dependent upon the coerced help of Margabandhu, a faculty member of the college. While Raja's skills as a medical doctor are minimal, he transforms those around him with the "Kattipudi Vaithiyam" ("hugging therapy"), a method of comfort taught to Raja by his mother. Despite the school's emphasis on mechanical, impersonal, and often bureaucratic relationships between doctors and patients, Raja constantly seeks to impose a more empathetic regimen. To this end, he defies all convention by treating a brain-dead man Anand as if the man were able to perceive and understand normally.
Vishwanathan, who perceives all this as symptoms of chaos, is unable to prevent it from expanding and gaining ground at his college. He becomes increasingly irritable, almost to the point of insanity. Meanwhile, Janaki becomes increasingly fond of Raja, who, in his turn, becomes unreservedly infatuated with her. Vishwanathan tries several times to expel Raja, but is often outsmarted by him.
Margabandhu's senile father is admitted to the hospital, and all hope seems lost for him. Having threatened Margabandhu before, Raja's gang knows that he is a passionate board game player, and Raja orders a carrom board to come to the hospital. Raja and his gang play carrom, and Margabandhu's father miraculously wakes up and walks to the board. Raja and Margabandhu's father play against each other, and Margabandhu's father wins the match and celebrates.
Upon recovery, Vishwanathan orders Raja to leave and brings police to throw him out, but everyone in the college protests and blocks the way. Vishwanathan tells the students the truth about Raja, but no one believes him. Vishwanathan promises to retain Raja if he answers all questions asked by the doctors in front of the entire university, a challenge Raja accepts. Despite preparing well, he is unable to focus as patient Zakir's condition becomes worse and he dies in Raja's hands.
The next morning, Raja starts answering the questions well, but Vishwanathan stops the staff and says he will ask all the forthcoming questions. Raja is unable to answer and is shamed into leaving the college. He confesses the truth to everyone. Everyone except Vishwanathan is moved to tears by his speech. Immediately following Raja's departure, Anand miraculously awakens from his vegetative state; Janaki criticises her father for having banished Raja. Vishwanathan eventually realises his folly.
Raja later marries Janaki while also reconciling with his parents.