As a child, Silver was kidnapped by the Masked Man along with several other children. There, he met and befriended a young girl named Blue. After spending several years being trained by the Masked Man, Blue led an operation for her and Silver to escape the Masked Man when his guard was down. After successfully managing to run away, the two began to work together to put an end to the Masked Man's ambitions.

Spoiler

Silver's special skill, as described by Dr. Yukinari Okido, is Pokémon trading (taught to him when he was with the Masked Man), and he is known as the "Exchanger".