A?oka is an epic historical period drama. The movie is based on the early life of Emperor Asoka of the Maurya dynasty. Asoka is not on good terms with his elder half-brother Susima Maurya (Ajith Kumar), and defeats him in a fight. Having fought his half-brother, Empress Dharma, Asoka's mother, asks him to leave the capital and lead a life of a common man. Asoka disguises himself as an ordinary traveller and travels to the South and meets a lovely maiden: Kaurwaki (Kareena Kapoor), and the two fall in love with each other. Later, Asoka realizes that Kaurwaki is a princess of Kalinga, and the two secretly get married. Sometime after, he is tricked to believe that Kaurwaki and her brother were assassinated. Angered, Asoka prepares for the war and attacks Kalinga. The Maurya soldiers kill everyone in the sight. Seeing the amount of bloodshed, Asoka realizes what he has done. He decides to give up the violence and embrace Buddhism and bring peace in the world.