Tsutomu Kojima is the primary technical advisor and computer operator for the Earth Defense Class, a team of elementary school students charged with Earth’s protection. Distinguished by thick glasses and a quiet, reserved demeanor, his analytical intellect and studious focus drive him to prioritize research and precise problem-solving. He oversees the monitoring and optimization of the group’s robotic systems, notably Raijin-Oh and its components, conducting rigorous analyses to refine their operational efficiency and unlock their full potential.

A familial bond ties him to Takako Kojima, a scientist affiliated with the rival Saurers team, for whom he holds profound respect. While their dynamic remains narratively unexamined, this linkage positions him as a conduit between technical mastery and inter-faction collaboration.

In combat scenarios, he employs systematic strategies to neutralize threats from antagonistic forces. His role transcends tactical planning, extending to diagnosing mechanical malfunctions, discovering latent system capabilities, and maintaining the team’s operational readiness during pivotal confrontations.