Summary:

In a world where reality is constantly falling apart, the pokemon gods have created assistants to keep it in check. The god of time, Dialga, has entrusted the upkeep and management of the ever unstable nature of time to thousands of Celebi who travel through time to keep things flowing normally.
Usually, changes to history and future occurrences by Celebii are integrated into a stable fashion assuring that history does not change. However, one such timekeeper has learned that he has the ability to actually change events, causing dangerous paradoxes that threaten reality as it is known.

Summary:

A young boy named Luke who has the ability to talk to pokemon, meets a Zorua named Mina behind his school. At the age of thirteen, he and Mina set out on their grand adventure. However, all is not well in the Unova region as an evil crime syndicate rears its ugly head.
With a seemingly limitless amount of money at their disposal, they have their eyes set on making life difficult for just about everyone.