Surya is a do-gooder who is liked by everyone around him except his father, who constantly puts him down because he is unemployed. When he goes around asking for money to save a young girl, all the people he had helped in the past turn him down. Surya decides to teach them the importance of helping others in his own way.
We have seen movies with a message but Yasakhan is the kind of movie where the entire movie is a message. Its protagonist Surya is someone whose only job in life is to do good. He even withdraws from an interview because the job will benefit his friend whose family has shunned him after he eloped and married a girl of his choice! Throughout the first half, we see Surya doing nothing but help — he volunteers to pay the electricity bills for a neighbour, changes the bed clothes of a hospitalized one (who promptly utters a cliched dialogue: "petha pullainga kooda ippadi panna maataanga"), promises to take a child to the park and even takes on a group of scoundrels who are molesting a girl. The last one even gets him arrested and only invites more condemnation from his father who constantly puts him down.
These scenes of doing good are interspersed with a lifeless romantic track between Surya and Shalini ( Niranjana), the daughter of his father's friend. She constantly woos him but we just cannot fathom why he falls in love with this girl, who often gets him into trouble with his dad. And they break into listless duets to make us cringe further.
The plot finally kicks in when Surya is forced to approach those whom he had previously helped to collect money to save a young girl. They all refuse and worse, one of them even accuses him of stealing Rs 5 lakh. This stuns Surya, who suffers a mental breakdown. We are told this is split personality disorder but the only personality that he shows is that of an insane man, roaming the streets with a vacant stare. His parents and his self-centered sister — an interesting character who becomes a caricature after a point — seem to have abandoned him, despite his father proclaiming melodramatically that he always loved him despite yelling at him often. His neighbours and friends (including the one for whom he withdrew from the interview) shun him and the only person who stands by him is Shalini.
And, just when we reach the limits of our frustration over why no one bothered to hospitalize such a mentally ill man, we get a twist that only makes us groan. We get a longwinded lecture on being human and helping others and for a moment, we think we are not in a movie theatre but in a seminar hall. Sadly, believing this seems easier than believing a lot of things that Surya does in the film.