In the underground Diamond Domain, where many Carbink live, the Mythical Pokémon Diancie serves as ruler. The Heart Diamond that sustains the land is beginning to fall apart, and Diancie is not yet strong enough to create a new one. While seeking help from the Legendary Pokémon Xerneas, Diancie encounters a group of thieves who want to take control of its diamond-producing power—and who awaken the Legendary Pokémon Yveltal from its cocoon in the process! Can Ash and his friends help Diancie discover its true power, stop Yveltal’s rampage, and save the Diamond Domain?
A princess of the Diamond Domain. She has set off on a journey to meet Xerneas in order to gain the power to make the Heart Diamond, the source of the Diamond Domain’s energy.
It was living peacefully in the Diamond Domain, but has set out on a journey with Diancie.
Called Life Pokémon, it is said to give life to people and Pokémon. Legend says that this Pokémon was the only one who could compete with Yveltal’s power during the rampage.
The Pokémon who caused the rampage, which took the lives of many in the Kalos region. Having destroyed everything, it now lies asleep in a Cocoon of Destruction.
Millis’s father. He owns a large airship and loves chocolate.
Argas’s daughter. She’s gone to save Diancie, who’s been kidnapped by Team Rocket. Her partner is Chesnaught.
A ninja thief whose face is hidden by a mask and is targeting Diancie. They are partners with Greninja.
A beautiful thief who is targeting Diancie. She is partners with Delphox.
A boy aiming to be a Pokémon Master who embarks on his journey together with his Pikachu.
A girl living in the Kalos region who loves fashion. Could it be that she’s met Ash before…!?
A boy Gym Leader. He is a good inventor, and has equipped his backpack with his pride and joy, the Aipom Arm.
Clemont’s little sister. She’s looking for a wife for Clemont. She is a girl of firm character.
An evil organization led by Giovanni to conquer the world. Jessie, James and Meowth of Team Rocket seeks to capture Ash’s Pikachu.
Pokémon: Pikachu, What's This Key?
The “Key Ring” Klefki appears in front of Pikachu and its friends. Using its on the mysterious keyhole that floats in the air before them reveals a strange and magical realm. It seems that Klefki holds the key to different worlds. What world will Pikachu’s key lead everyone to?