The setting is 2019 Central Tanegashima High School in Kyushu, Japan. Kaito Yashio and Akiho Senomiya are the sole members of the Robotics Club. Kaito is a careless student and active gamer who has taken up the task of helping Akiho, his energetic childhood friend. Akiho aims to complete the ongoing project of the club: completing a fully functional replica of Gunvarrel, the main robot in a once popular TV series. When they gather more members and continue to try to assemble the robot, Kaito starts stumbling upon secret reports that might reveal a conspiracy of epic proportions. Unaware of what he is actually dealing with, Kaito begins discovering clues hidden by Ko Kimijima.