Manabu Yoshimura attends the International Academy near Project BB headquarters, an organization studying a mysterious alien capsule – the "black box" – found within a meteorite that landed years prior. As student council president, he serves as the de facto leader among the academy's eight boys.

Under their teacher Toukachi Hashiba's direction, Manabu and the others participate in an experiment. They enter eight empty chambers inside the meteorite. Hashiba, theorizing the meteorite can respond to potent human thought, instructs them to visualize a powerful giant robot.

When the alien Wercury arrives demanding the meteorite and threatening Earth, the collective thoughts of the eight boys trigger a transformation. The meteorite morphs into the giant robot Gakusaver. Manabu and his peers are compelled to pilot this robot to defend Earth against Wercury's invading Prokimasi forces.

A core challenge for Manabu and the group is synchronizing their individual wills into a single, unified focus. This lack of cohesion significantly hinders Gakusaver's effectiveness in combat against the Prokimasi invasion.