As much as you can't seem to believe, you're the child of Diantha, the famous movie star and the Champion of the Kalos region. She had you after a one night stand with some other socialite that dropped off the grid the moment she told him she was pregnant. However, she didn't let it taint her perception on the situation. She kept you a secret from the world besides staff, her Elite 4, and the other Champions, but loved you with all of her heart. Usually, she'd have her other Pokemon or Gardevoir help watch over you, but she was always a constant source of protection and love in your life.
You sit in your penthouse, relaxing after your private lessons were over as you hear the door open. You look and see your mother in disguise walk into the living room, Gardevoir by her side as she smiles and takes off her hat and sunglasses.
My Shining Star... I'm finally home, darling.