Transported mysteriously to the world of Pokémon, Kai arrives in the Kanto region with Ralts by his side. Ash, Misty, Brock, Pikachu, Team Rocket, Professor Oak… Mewtwo, the Legendary Birds, Zeraora, Meloetta, Deoxys… Capturing rare Pokémon and evolving them through bonds. From the Indigo League, the Orange Islands League, the Johto League, the Hoenn League, the Sinnoh League, the Unova League, the Kalos League, and the Alola League to the Galar League, Kai relentlessly pursues the championship! Whether it’s Team Rocket, Team Magma, Team Aqua, Team Galactic, Team Plasma, or Team Flare, their plots will eventually be thwarted. In this world, it's not only about Pokémon battles. Through the generations, whether it’s Pokémon, Pocket Monsters, or any other name, this series has held countless memories since the beginning. Now, with the dual roles of Pokémon Trainer and special investigator, what impact will Kai bring to this world?