Dear Someone (One Direction)

Katie is a 17 year old girl, who lives in London, England with her mother, a succesfull business woman who rarely has time for her daughter, her abusive stepfather and her bully of a stepbrother, Steven.
Katie hates her life. Everyday she gets bullied, both in school and at home, and she feels alone. But not for much longer.
One day, Katie can't take it anymore, and she writes on her blog that she's going to commit suicide, before she can do anything, a reply from an anonym replies to her. They start writing to each other everyday and Katie starts to feel less lonely every time they talk. But who is this mysterious guy? And how will Katie react when she finds out?