Hareta grew up in the wild among Pokémon and can climb like an Aipom and swim like a Magikarp. Professor Rowan recruits him as a Trainer, hands him a Piplup and sends him out with Mitsumi to find Dialga, the legendary Pokémon at the center of Sinnoh's folklore. Team Galactic wants Dialga too, and its recruits start turning up wherever Hareta goes. The manga follows the Diamond and Pearl games rather than the anime.