In the city of Tsutsujidai, a mysterious amnesiac high school student named Yuta Hibiki finds himself haunted by a strange voice, one that guides him toward a hidden computer terminal. There, he discovers his calling to merge with a colossal being known as Gridman, a hyper-agent from the Hyper World, to battle monstrous kaiju that emerge without warning, wreaking havoc on the city. Alongside his classmates, the determined Rikka Takarada and the tech-obsessed Sho Utsumi, Yuta must piece together the truth behind the monsters and his own forgotten past. As they fight these towering threats, they begin to realize that the very fabric of their reality may be at stake, and that the quiet, unassuming citizen Akane Shinjo holds secrets far more terrifying than any monster. This anime masterfully blends high-octane mecha action with a slow-burning, psychological mystery, creating a gripping and visually stunning atmosphere that questions the line between hero and creator.