In 2019, Kaito Yashio and Akiho Senomiya are the sole members of the Robotics Club at Central Tanegashima High School in Kyushu, Japan. Kaito is a laid back student and a skilled gamer who is just trying to help Akiho, his childhood friend. She is an energetic positive-thinking girl who yearns to complete the ongoing project of the club: building a functional replica of Gunvarrel, the main robot of a once popular TV series. As they gather new members and try to assemble the robot, Kaito starts stumbling upon secret reports that might reveal a conspiracy of large proportions. Unaware of what he is actually dealing with, Kaito little by little starts discovering clues laid by the mysterious Ko Kimijima.

Rie Kugimiya, Kaori Nazuka, Ryohei Kimura, Sora Tokui, Yoshimasa Hosoya, Yoshino Nanjo