Taking place in Sinnoh, the Pokémon world version of the Japanese island of Hokkaido, the plot is familiar territory for the series: you, a child from the modest little village of Twinleaf Town, and your hyperactive best friend, have a fateful encounter with Professor Rowan, the local authority on Pokémon, and his well-meaning but inexperienced assistant. The fourth generation of Pokémon games, Diamond and Pearl hit the Nintendo DS in Japan in 2006 and the rest of the world in 2007.
Blurb on the back of the boxes of Pokémon Diamond and Pearl Versions