Kaito Yashio and Akiho Senomiya are the only members of the Central Tanegashima High School Robotics Club in Kyushu, Japan, in 2019. Kaito is a mellow student and great gamer who is merely attempting to assist his childhood friend Akiho. She aspires to complete the club's ongoing project, which involves constructing a functional duplicate of Gunvarrel, the main robot from a once-popular television series. As they recruit additional recruits and attempt to assemble the robot, Kaito begins to discover hidden reports that may reveal a vast conspiracy. Kaito gradually begins to uncover hints left by the mysterious Ko Kimijima, unaware of what he is actually dealing with.