The story starts when you save Pokémon Professor Birch as he is being attacked by a wild Pokémon. He runs the Pokémon Lab in Littleroot Town. When you save Professor Birch, you will have your first meeting with the Pokémon that will become your partner on your journey, and a new bond will be born.
Birch has been good friends with your father, Norman, since their school days. He has a tendency to get enthralled with Pokémon and leave home for long periods.