From Viridian Forest to Terminus Cave, see the Pokémon world as never before!
The episode begins with the intro screen of Pokémon Red and Blue, with the player resuming a saved game. The player character, simply named "Trainer", is walking through Viridian Forest in the Kantoregion, where he quickly encounters a wildPikachu. One Poké Ball later, the Pikachu is caught. The scene then transits from game environment into proper animation, with the Trainer, Red, picking up the Poké Ball containing the newly caught Pikachu. He sends it out again, and it begins to explore its surroundings. It quickly encounters a Caterpie, which attacks with String Shot, but Pikachu successfully dodges the strings before counterattacking, just as Zapdos flies past the screen.
The scenery changes, now depicting Pikachu climbing up a tree in Ecruteak City in the Johto region. It fires a Thunder Shock at a group of Wooper in the river below, but the Ground types are unaffected by the attack, and strike back with Mud Shot just as Lugia flies by, sending Pikachu flying.
Now Pikachu is battling a Vigoroth outside of the Weather Institute at Route 119 in the Hoenn region. The two battling Pokémon make their way across the nearby wooden bridge while being observed by Latios and Latias. Suddenly, the battle causes the bridge to start collapsing, making both Pokémon rush to the other side to avoid falling down.
Outside of the Snowpoint Temple in the Sinnoh region, Pikachu is battling a Probopass, whose Mini-Noses keep attacking it with beams of energy. The commotion, however, causes Regigigas to wake up and emerge from the temple. After easily smacking Probopass aside and shrugging off Pikachu's Electric attack, the Legendary Pokémon unleashes a devastating attack around itself.
In the Desert Resort in the Unova region, Pikachu and Red enter the Relic Castle. Pikachu accidentally falls into a sand pit, causing it to fall into a deeper part of the castle, where it comes face to face with Volcarona. The Bug/Fire Pokémon attacks Pikachu with Heat Wave, but Pikachu uses Iron Tail on a floor tile, using it to block the attack. Pikachu then counterattacks with Volt Tackle, defeating Volcarona. Just then, Landorus emerges from underneath the floor and prepares to attack Pikachu.
Now in Terminus Cave in the Kalos region, both Red and Pikachu are riding a mine cart while being attacked by a wild Noivern. Noivern attacks the two with a narrowly missing Dragon Pulse, while Pikachu strikes Noivern with Electro Ball. The attack momentarily grounds Noivern, but it quickly recovers, now attacking with Boomburst. Before the attack can hit, however, Pikachu counters with a Thunderbolt, defeating Noivern. At the end of the mine cart ride, Red and Pikachu encounter Zygarde in its Complete Forme. A bright pillar of light forms around the Legendary Pokémon, forcing Red to momentarily cover his eyes as Zygarde begins to ascend into the sky through a hole in the cave ceiling. The camera pulls out to show the entire planet as the title "Pokémon Generations" appears on the screen.