Aval Peyar Tamilarasi is set in a village in South Tamil Nadu (India). 

Even as a child, Jothi Murugan (Jai), who lives with his grandfather at the village, starts liking Tamilarasi (Nandagi), who has come to their village with her family, which includes her brother, mother and grandfather (Theodre Bhaskaran). He starts liking them and pleads with his grandfather to help them. His grandfather helps and makes them stay in the village which enables him to spend more time with her.

As they grow together, Jothi becomes very fond of Tamilarasi and does everything for her so that she is happy. For Jothi, Tamilarasi is everything in his life. However, Tamilarasi in order to come out of her poor family situation, studies well in every class and finally emerges as the topper in the district in the Public Examination. Jothi due to his playful attitude and wrong friendships ends up failing in the examination.  This leads to an inferiority complex in him and a feeling that, he will be ditched by her soon.

Though both Tamilarasi and her family always think of Jothi as the benefactor of the family and trust him for everything (including making her stay with him in the same room, when they travel outside the village to attend an entrance exam), Jothi’s friends misguide him stating that, since she is a topper in studies and also has got admission to higher studies in a city far away from their village, she might soon ditch him and marry someone else. Jothi is unable to accept a life without Tamilarasi. Jothi is confused and starts distancing himself from Tamilarasi, when he comes to know that Tamilarasi has gone for counseling for higher studies, without him to a nearby city.

When Tamilarasi returns, dramatic changes occur in their lives and that forms the rest of the story.

The underlying message is, one must think of the consequences before taking any hasty decision and implementing the same in life. A single action in the life of a man can change the way his life shapes up. A single wrong decision can change his or her life forever.

The film is visual poetry, capturing various art forms and festivals thus giving the audience a chance to experience the rich culture of Tamil Nadu and Maharashtra. Of course there is also the subtle love story being told as well.