Synopsis
In the year 20XX, enormous enigmatic robots called "Giant Robo (GR)" begin to appear around the world, destroying cities and plunging Earth into fear. Their next target is Japan. The story's hero, Daisaku Kusama, who works at a diving shop, encounters a mysterious girl known only as V. She leads him to an ancient ruin on Minami Yonaguni Island in Okinawa, where he forms a contract with the massive robot "Giant Robo 1 (GR1)." Daisaku then allies with UNISOM (the good side) and is approved as the commander of GR1. His battle against GRO (the evil side) commences, generating many dramatic events. Before long, the Giant Robo of the 21st century will pose a question to the world about the true meaning of its power.