1000 years ago Celestia was forced to use the elements of harmony to seal her younger sister in the moon. Unfortunately it didn't just seal her in the moon alone, celestia's last wish before finalizing the spell to seal nightmare. Was that she wouldn't have to bear such a terrible loneliness during banishment. That wish however took a familiar human living his everyday life and forced him and nightmare to share the same body. How will he convince her to let go of her grudge against her sister and embrace her old self as Luna?