Blue Oak is the grandson of Professor Oak and was the first to receive a Pokédex. Through tough training, Blue increases the level of his Pokémon, making them apt to dispute in battles against the best Trainers, even using the ones he raised from scratch. Due to his skill, he is defined as the Trainer. While he disliked the fact that Red also had a Pokedex at first, they become good friends and rivals. He later becomes the Gym Leader of the Viridian City Gym.