Pocket Monsters Diamond & Pearl

Pocket Monsters Diamond & Pearl is a manga series created by Sakai Takayuki. It is based on the Pokémon anime, taking place in the timeline of Pokémon the Series: Diamond and Pearl. The stories feature Ash and Dawn's adventures. Unlike other manga adaptations of the anime, Pocket Monsters Diamond & Pearl features original stories rather than adaptations of the plotlines of specific anime episodes.

(Source: Bulbapedia)