In 2019, modern technology is highly developed, and robots are popular in all aspects of the human world. The Central Tanegashima High School Robotics Department is a small group of only two people. Yashio Kaisho (played by Kimura Ryohei), who is obsessed with handheld games, and Senomiya Akiho (played by Nanjo Aino), the director who loves robots very much, are facing the situation of abolishing the department due to too few people. Xiaoqiu dreams of taking the department's biggest dream-the same-size robot GUNVARL to participate in the Tokyo City Expo held next year. In order to successfully obtain funds, the Robotics Department must win the ROBO-ONE competition. After the twists and turns and exciting competition, the Robotics Department survived smoothly and also absorbed Hidaka Subaru (played by Hosoya Yoshimasa), who has a very high talent in machinery. The construction of the giant robot is proceeding in an orderly manner, the magnificent dream is blooming, and the shadow of the conspiracy is quietly shrouding Tanegashima. All of this is closely related to the events nine years ago... This film is adapted from the original work of Shikura Chiyomaru.