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?

Life goes on when there's a break in the kaiju attacks. However, when Akane's world comes crumbling down, the Gridman Alliance might need help to battle her broken heart.