"Rewrite" is a 24-episode anime adaptation of the visual novel by Key, blending elements of fantasy, science fiction, and supernatural drama. The story unfolds in the fictional city of Kazamatsuri, known for its lush greenery and unique urban planning. The protagonist, Kotarou Tennouji, is a high school student with a penchant for getting into trouble. He possesses a mysterious ability to "rewrite" his body, granting him enhanced physical capabilities, though the origins of this power remain unclear initially.

Kotarou becomes involved with the Occult Research Club, a group of classmates who share his curiosity about the supernatural. The club includes Kotori Kanbe, a cheerful and energetic girl with a deep connection to Kotarou’s past; Chihaya Ohtori, a stoic and physically strong transfer student; Lucia Konohana, a disciplined and sharp-tongued classmate; Shizuru Nakatsu, a kind and nurturing upperclassman; and Akane Senri, the enigmatic president of the club. Each character harbors secrets tied to the overarching mysteries of the series.

The narrative explores two primary factions vying for control over the fate of humanity: Guardian, an organization dedicated to protecting the planet by eliminating threats to its ecosystem, and Gaia, a group seeking to transcend humanity’s limitations by merging with the planet itself. Kotarou and his friends become entangled in the conflict between these factions, uncovering their own roles in the larger scheme. Guardian employs "familiars," supernatural beings created to combat threats, while Gaia utilizes "Key," individuals with the potential to rewrite reality.

As the story progresses, Kotarou learns more about his abilities and their connection to the city’s hidden history. The series delves into themes of environmentalism, human evolution, and the consequences of tampering with nature. The characters’ personal arcs intertwine with the central plot, revealing their motivations and the sacrifices they must make. Kotarou’s relationships with the members of the Occult Research Club deepen, and their bonds are tested as they confront increasingly dire challenges.

The anime adapts multiple routes from the visual novel, blending them into a cohesive narrative that balances action, mystery, and emotional depth. The final episodes escalate the stakes, culminating in a climactic confrontation that determines the future of humanity and the planet. "Rewrite" combines intricate world-building with character-driven storytelling, offering a layered exploration of its central themes while maintaining a focus on the personal journeys of its cast.