From Bulbapedia, the community-driven Pokémon encyclopedia.
Screenshot from the ending video.
W Mission Story: Pokémon Ranger - The Comic (Japanese: W ミッションストーリ ポケモンレンジャー the Comic) is a manga based on the W-Mission of Pokémon Ranger. It is written by 日下秀憲 Hidenori Kusaka and illustrated by 山本サトシ Satoshi Yamamoto. It is set in the same continuity as Pokémon Adventures, as evidenced in PS441. A manga featuring the game's sequel, Shadows of Almia, was also released under the name "Darkrai Mission Story: Pokémon Ranger Vatonage - the Comic".
The manga was available online to members of the Pokémon Daisuki Club, and has never been printed as a bound volume.