On a new day in the Kanto region, Satoshi gets invited by Professor Yukinari Ookido over to Professor Sakuragi's lab-opening ceremony in Vermillion City. During the ceremonial speech, Professor Sakuragi receives an alert of a possibly rare Pokémon appearing in Vermillion City's harbor, leading Satoshi and the other trainers to rush to the area in hopes of finding the mysterious Pokémon. At the harbor, they find Lugia—a Legendary Pokémon—engaged in combat with other trainers. Noticing the other trainers' tactics, Satoshi has his partner, Pikachu, strike Lugia with a Thunderbolt attack. Unfazed, Lugia flees, but not before Satoshi determinedly leaps onto its back. To Satoshi's surprise, he meets another boy, Gou, who leapt onto Lugia's back as well. The two ride on Lugia's back as it brings them along on a bizarre adventure across the seas. As it lets the two back on the ground, Satoshi and Gou bid their farewells to Lugia and return to Sakuragi Institute. Impressed by Gou's findings and Satoshi's insight taken during their encounter, Sakuragi requests for the duo to be his new research partners. And so the duo's journey begins, traveling across multiple regions to meet many new Pokémon—including ones that have the ability to Gigantamax!

Shidou Itsuka faces greater peril than ever due to his continued involvement with Ratatoskr. He has already sealed 10 Spirits, and Isaac Westcott, leader of Deus Ex Machina Industries, has finally decided to kill Shidou and plunder the Spirits' powers for himself. To achieve his goal, Isaac declares an all-out war against Ratatoskr, forcing the organization to exhaust its resources to ensure Shidou's survival. Despite being severely outnumbered and outmatched, a glimmer of hope exists in the form of the Spirit of Time, Kurumi Tokisaki. Shidou must seal and acquire Kurumi's power to travel to the past and confront the Spirit of Origin—the catalyst that started it all.

Akane Nishimura's quiet nature makes her classmates perceive her as a gloomy and unlikeable person. Combined with her intimidating gaze, it earns Akane the ominous nickname "Grim Reaper," condemning her to endless bullying for her supposed cursed powers that bring misfortune to everyone around her. However, none of these rumors deter transfer student Taiyou Takada from trying to befriend Akane. As someone who finds the supernatural fascinating, Taiyou approaches the Grim Reaper without hesitation, blissfully unaware of the complicated situation within the class. His bright personality and optimistic worldview may just bring about the change that Akane desperately needs.

Crime-ridden Ikebukuro is a haven for violent gangs, the Yakuza, and home to Makoto Majima. To protect his friends, this charismatic troubleshooter mediates disputes among the warring factions—even fixing problems the police can't. But when a rising tide of violence results in Makoto losing a loved one, can he ride out the storm, or will he drown in all the spilled blood that floods his streets? (Source: Funimation)