Giratina is the sole Pokémon living in the Reverse World, a little-known realm adjacent to our own. Enraged when Palkia and Dialga disrupt time and space, it drags Dialga into the Reverse World for a battle—but the conflict is broken up by a tiny Shaymin, the Gratitude Pokémon!
After departing the Reverse World and meeting Ash and his friends, Shaymin—communicating telepathically—asks for help so it can be reunited with the other Shaymin in the Gracidea garden.Soon after Ash and his friends agree to assist Shaymin, they're dragged into the Reverse World and meet Newton Graceland,
who's been researching the mysterious realm. Little do they know that Newtown's former assistant, Zero, seeks to harness Giratina's power to rule the Reverse World, even if that means destroying the real world!
Can our heroes and their Pokémon thwart Zero's evil plans and protect both worlds? Will Giratina resolve its differences with Dialga? And what will Ash and his friends learn about that special Shaymin?
A Pokémon with the trait “Flower Bearing”. Afterwards, it sets off on a journey with Ash to search for the garden. It can perform Formechange.
A Pokémon living in the Reverse World. Angered by pollution in the Reverse World, it goes after Dialga. It can perform Formechange.
A Pokémon who sleeps deep within a glacier. Awakened by crisis on the glacier, it tries to prevent the glacier from collapsing.
Pokémon living near the glacier. Appears in huge herds along with Regigigas.
Partner Pokémon to Newton, who researches the Reverse World. He works to help Newton and Ash.
A boy aiming to be a Pokémon Master who embarks on his journey together with his Pikachu.
A new Pokémon Trainer from Twinleaf Town. Influenced by her mother, a distinguished Pokémon Coordinator, her dream is to appear in the Pokémon Contest.
The former Gym Leader of Pewter Gym from Kanto. He is knowledgeable about Pokémon and is good at cooking, too. He is on his journey to become a Pokémon Breeder.
An evil organization led by Giovanni to conquer the world. Jessie, James and Meowth of Team Rocket seeks to capture Ash’s Pikachu.
A mysterious young man who controls the high-tech mothership. He is trying to use the power of Giratina to control the world.
A brilliant scholar who is researching the Reverse World. He has spent five years researching the Reverse World.