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?

The others are finding Yuta's story hard to believe. Nobody wants to confront and ask Akane, but in the meantime, Anti has made plans of his own.