V. C. Selvam, a history professor, is appointed as the vice principal of Sakthivel Arts College, which is riddled with students' unrest and conflicts. Ramesh, son of a major donor to the college, is a spoiled brat and campus bully who influences other students by his vulgar display of money and power. Sparks fly between Selvam, who tries to bring in some order in the college, and Ramesh, who tries to spoil it from their first interaction.

Selvam brings in changes. Students join together to paint the campus and bring in a clean look, introduces discipline in reporting time for professors and students, closes the canteen during lectures and opens a cultural centre for students. By adopting a different teaching technique, Selvam helps students to gain more focus.

Vasanthi, a professor in the same college, initially disapproves of Selvam's methods, but finally finds them beneficial for the students and falls in love with him despite his initial resistance. Ramesh becomes displeased with the changes and is vexed at losing control over the students who are moving to Selvam's side.

Ramesh tries to provoke Selvam, who does not respond. Ramesh injures himself and frames Selvam, which instigates the students to call for a strike. Despite many students supporting him, Selvam apologises for the sake of peace in the college. When Ramesh tries to derail the students' plan of participating in an inter-college cultural competition by destroying their musical instruments, Selvam uses the students' skills to create a cappella music and wins the competition.

After a student is hospitalised and needs blood urgently, Selvam chooses not to donate his blood, instead organising a donor. Vasanthi is disappointed at Selvam's decision and learns through his aide Perumal that Selvam has blood cancer; his days are numbered. Shocked, she resolves to marry Selvam soon. Though Selvam does not initially reciprocate, she manages to convince him. She also learns of Selvam's desire to seek answers to fight his inner demons by doing good to the college.

Ramesh is suspended from college for drug dealing. He kidnaps his former friend Vijay's (who started supporting Selvam) girlfriend Nirmala, daughter of professor Prabhakar Rao, and implicates her in a brothel case, leading to her arrest. Though Selvam bails Nirmala out, she commits suicide out of disgrace. This provokes Vijay into trying to kill Ramesh.

During the fight against Ramesh, Vijay is stabbed and Selvam comes to his rescue. Selvam is also stabbed, and people start throwing stones at Ramesh, but Selvam rescues him. Ramesh soon realises he is alone in the conflict; everyone in the college has deserted him. Selvam asks the students to forgive Ramesh and give him a second chance, which makes Ramesh repentant. Afterwards, Selvam and Vasanthi decide to leave to the United States seeking a cure for the cancer, hopeful that the college will be truly reformed when they return.