I am number four

The film is about aliens who fled their planet and are chased by another enemy species is based on the history of the number 4  who is constantly changing identity to avoid being discovered  he does not like to be changing.

He and his father moved to another city along with another false identity, but this time was different because the number four became involved with new people she met, fell in love with a girl, got a best friend to share his secret discovered that he had new powers, foughtthe enemy with the number 6 and lost his father.

To end the battle with their enemies decides to go back and let the girl but with the promise to return.