Long ago, Arceus granted a fragment of its power as the Jewel of Life to help Michina in the town’s hour of need, only to be betrayed when it was time for that power to be returned. After so many years, Arceus is about to return to reclaim its stolen power- enraged, vengeful, and seemingly unstoppable. Not even the combined might of Dialga, Palkia, and Giratina can stop Arceus from devastating all existence across the dimensions. But Ash and his companions, joining forces with their new friend Sheena, May have discovered the only way to redeem that ancient betrayal. Their journey will be both dangerous and uncertain: even if Ash and his friends can set an old wrong right again, will there be time to return the Jewel of Life before Arceus destroys everything and everyone they’ve ever known?
In the town of Lohta, a festival is thrown praising “Aaron the Wave Leader Hero” who, according to the legend passed down through the town’s generations, stopped a war centuries ago by using the power of “the Tree of the World’s Origin.” Satoshi and Pikachu participate in a battle to decide this year’s hero and after their victory, they are chosen as the “Wave Leader Hero.” A grand dance party is held in the castle to celebrate the victor, but suddenly the phantom Pokemon Mew appears and takes Pikachu. Soon afterwards, the Wave Leader Pokemon “Lucario” is freed from his centuries-long seal and meets Satoshi. Satoshi must solve the various mysteries of where Pikachu is, what Mew’s after, what the secret of the legend of the Wave Leader is and how it ties in with Lucario’s hidden past as he makes his way to “the Tree of the World’s Origin” with Lucario.
This movie centers around the new pokémon Celebi, a one-of-a-kind veggie-like bug whose only kin are celebi from other points in time. The movie begins in the past where a young boy named Sam attempts to save Celebi from a hunter. In a reciprocal effort, Celebi uses his power and transports itself and Sam to the present, Ash Ketchum’s time. Sam and Ash become good friends as they fight to save Celebi from the new Team Rocket villain, the Iron-Masked Marauder and his darkball, which turns pokémon evil and augments their powers to the maximum. Yet, one rare pokémon isn’t safe without help from another – thus enters Suicune, a.k.a. the North Wind.
Ash, Pikachu and the rest of the Pokemon gang try and stop a pair of thieves hiding out in the canals and alleyways of Alto Mare, the water capital of the world. Joining the adventure are two new Pokémons, a brother/sister pair named Latias and Latios who are protecting the Droplet of the Heart – a valuable treasure.