Pokémon Adventures: Gold, Silver & Crystal

Story

This chapter features the journeys of Gold through Johto trying to at first search for the ones who stole his backpack and uncovers that the ones who stole his backpack are planning something. Two other new Trainers come into the plot of the story, Silver, whose life is tied in with the villains of this series, and Crystal, an average Pokémon Trainer with a staggering talent in catching Pokémon who later helps Professor Oak catch all the Pokémon to complete his Pokédex. Along with these three, the original 3 Pokédex holders come back to help these three along with Yellow.

Synopsis via AniList (English).