Rie does not remember her life between the ages of 7 and 14, save for one memory of staring at her hideously deformed face in a mirror, with her mother sitting beside her. However, Rie is now beautiful and no one can remember her ever being any other way. There are few photographs of her during the time of her memory loss, but of those that exist, they all show her looking as she is now.
Rie's parents dismiss her concerns, but she overhears them talking, and confirms that something which she has now forgotten did occur during her childhood. They mention one remaining photo from during that time. Rie finds it and sees the hideous face she remembers. She believes that it is an evil side of herself, like Jekyll and Hyde, that controlled her between the ages of 7 and 14.
Rie becomes convinced that she is becoming ugly again and is about to lose her memories. She has a psychotic break and attacks her parents with a knife, screaming at them that they gave birth to an ugly monster. They bring a mirror and show her that she is normal. Finally, they tell her the truth. She had a deformed twin sister named Keiko and her memory is of her mother comforting Keiko beside the mirror while Rie watched. Rie became paranoid that she would grow to look like Keiko. Eventually she murdered Keiko in the belief it would stop her own anxiety. Her parents passed off Keiko's death as suicide and allowed Rie to forget Keiko existed.
Rie asks Keiko's spirit for forgiveness, and dances in front of the mirror, no longer worried that she will lose her memories or become ugly.