Ayato, a transmigrator struggling in the desolate, steampunk-influenced Orre region where wild Pokémon are virtually non-existent, is auto-enrolled into the second-rate Quicksand Team. He gains a "Trainer Life Simulator" system, allowing him to experience simulated journeys in other regions (like Kanto) and earn rewards, including clues and items.
During a perilous Quicksand Team assessment in an abandoned mine, Ayato encounters a wild Aron, drawn to an iron ingot he acquired through his simulator. When a rival grunt, Shibata, and his cronies ambush Ayato's friends, Aron assists in their rescue. In the ensuing chaos and mine collapse, Aron bravely defends Ayato from Shibata's Rhyhorn, sustaining severe injuries. Despite the danger, Ayato risks his life to return and save the injured Aron, solidifying an unspoken bond.
After surviving the ordeal, Aron officially becomes Ayato's first Pokémon. Now a full-fledged member of the Quicksand Team, Ayato must navigate its internal politics, the lingering threat from Shibata's vengeful uncle (a squad leader), and the significant financial and practical challenges of raising Aron in the resource-scarce Orre region, all while relying on his simulator for potential advantages.