Yuta Hibiki wakes up in the home of his classmate, Rikka Takarada, with amnesia. A voice from an old computer, identifying himself as "Gridman," has a mission for him, but can he even survive the next day of school without his memories?

It all comes down to the line as the Gridman Alliance attempts to save Akane, but do they have what it takes to battle the monster within?