"Pokémon Generations" is a short-form anime series that revisits key moments from the mainline Pokémon video games, spanning from the original "Pokémon Red and Green" to "Pokémon X and Y." Each episode focuses on a specific event, region, or character, offering a condensed yet faithful adaptation of iconic game moments. The series is structured as a collection of standalone episodes, with no overarching narrative connecting them, allowing viewers to experience a variety of stories from the Pokémon universe.

The series begins with episodes set in the Kanto region, depicting pivotal events such as the theft of the Pokémon fossils from the Pewter City Museum and the confrontation between Team Rocket and the legendary Pokémon Mewtwo. These episodes highlight the actions of both protagonists and antagonists, showcasing the moral complexities of the Pokémon world. The Johto region is explored through episodes featuring the legendary beasts—Raikou, Entei, and Suicune—and the efforts of characters like Eusine to encounter them. The series also delves into the Hoenn region, with episodes focusing on the clash between Team Magma and Team Aqua, as well as the awakening of the legendary Pokémon Groudon and Kyogre.

In the Sinnoh region, the narrative shifts to the creation myth involving Dialga, Palkia, and Giratina, as well as the ambitions of Team Galactic's leader, Cyrus. The Unova region is represented through episodes centered on the conflict between Team Plasma and the legendary Pokémon Reshiram and Zekrom, emphasizing the ideological divide between truth and ideals. The Kalos region is featured in episodes highlighting the bond between the player character and their Pokémon, as well as the climactic battle against Team Flare and the legendary Pokémon Xerneas and Yveltal.

Throughout the series, recurring themes include the relationship between humans and Pokémon, the consequences of human ambition, and the balance of power in the Pokémon world. The episodes often focus on secondary characters or events that occur off-screen in the games, providing additional context and depth to the established lore. While the series does not follow a continuous storyline, it serves as a celebration of the Pokémon franchise's history, offering fans a fresh perspective on familiar events and characters.