Pichaikkaran revolves around Arul Selvakumar, who's a rich guy of the city. One day, he realises that his mother's life is at stake and can't be easily saved. He tries his best, and at last, decides to become a beggar for 48 days, to save his mother. He even has a cute love story in between. He gives up every pleasure …

Embarrassed by the birth of a son, an unwed Kunthi (M.V. Rajamma) instructs her maid to abandon him in the river Ganga. The child is set afloat and is rescued, adopted, and named Karna (Shivaji Ganesan) by Charioteer Adhiratha and his wife, Radha. After maturing he does not want to follow in his foster father's footste…