Ash Ketchum, Dawn, Brock and their Pokémon arrive in Michina Town. As the group relaxes in a nearby river, some watermelons suddenly float towards them. While enjoying the watermelons with their Pokémon, a boy named Kato and his sister Kiko appear who justify that the watermelons were theirs and were kept to cool in the flow of the river. Kato and Kiko then challenge Ash for a tag battle in return of the watermelons. Ash and Dawn thus plan for a tag Pokémon battle against them using Ash’s Pikachu and Dawn’s Piplup against Kako’s Heracross and Kiko’s Beautifly. Ash and Dawn win the battle with good teamwork and also request Kato and Kiko to join for eating watermelons. After that, Kato and Kiko suggest Ash and the gang visit the local temple ruins. Whilst visiting a lake, a typhoon suddenly strikes up, but two mysterious individuals named Sheena and Kevin summon Dialga who ends the typhoon. A grudge Giratina arrives and attacks Dialga, but Sheena uses her ability to communicate with a Pokémon’s heart to quell their conflicts with each other, sending Giratina back to its dimension. Palkia then arrives to save Dialga from another typhoon, and Sheena, once again, uses her ability to sync with the two to thank them. Taking the kids to the temple, Sheena and Kevin explain that they investigate disruptions in time and space, and worry that Arceus, the creator of the dimensions, is to awaken, and that he is responsible for the encounters between Dialga, Palkia, and Giratina.