Krrish is a sequel to Koi Mil Gaya. Krishna (Hrithik Roshan) is born with magical powers, carrying on the legacy of his father, Rohit Mehra (Hrithik Roshan). He can run very fast, jump across rivers and mountains and is very naive as he has not seen the world outside his little hometown.
Then, one day, Priya (Priyanka Chopra) comes into his life and becomes his world. She ultimately goes back to her native place, Singapore. A television journalist by profession, Priyanka is impressed with Krishna's powers and decides to do a story on him, to save her job. When she calls him to Singapore, he follows, much to the dismay of his grandmother (Rekha) who is scared of losing him, the way she lost her son.
In Singapore, Dr Siddhant Arya (Naseeruddin Shah), a power hungry scientist is on the brink of a great discovery, something which was started by Rohit.
Only one man stands between Dr Siddharth Arya and his destructive dreams, and that is Krishna, but he must hide behind the alter ego of Krrish.