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?

Yuta e seus amigos tentam desvendar o mistério da cidade e das memórias de todos. Porém, um samurai surge e tenta mexer com o Gridman.

A new kaiju appears which poses a problem for Yuta and Gridman. As a result, Rikka and Utsumi are left wondering if their friend will end up long since dead, just like the other students.

Rikka and Akane are invited on a group date, but the aftermath is disastrous. Will Yuta be able to convey his feelings for Rikka before it's too late?

A field trip takes the class away from the city for some summer fun, but when trouble occurs so far from home, there's no easy way to get to Junk.

Encontros inesperados deixam Yuta e os outros em choque. Só que Gridman está sendo caçado e isso significa que Yuta está em perigo.