It is a story about a 13 year old boy Auro, played by Amithabh Bachchan. Auro suffers from progenia like syndrome, it's a rare genetic defect that causes a fast ageing. Mentally he is 13 yr old boy but physically looks 5 times older. He is a very smart boy and inspite of his condition he is a very happy. Auro is living with his Mother and Father. By profession his Mother, played by Vidya Balan is a Gynaecologist and his Father, Amol Arte, played by Abhishek Bachchan is a young, progressive politician. He is full of ideals and he wants to prove the world that 'Politics' is not a bad word. Paa is rare and unique story about Father-son, Son-Father relationship.