OVA
Description
Dr. Shizuma is a scientist who was part of a team of five researchers working on a new energy source in the fictional nation of Vashtal. This team included Dr. Franken von Fogler, as well as Drs. Trambo, Duncan, and Simre. After a catastrophic accident known as the Tragedy of Vashtal, which resulted in widespread destruction and the apparent death of Dr. von Fogler, Dr. Shizuma became celebrated worldwide as a hero. He was hailed for perfecting the Shizuma Drive, a revolutionary, clean, and renewable energy source that came to power nearly everything in society, from vehicles to small personal items.

Despite his public persona as a benefactor of humanity, Dr. Shizuma is a deeply troubled and guilt-ridden individual. He is haunted by the truth of the Vashtal disaster, as he and his surviving colleagues ignored von Fogler’s warnings and proceeded with a dangerous experiment using three imperfect prototype drives. The resulting runaway reaction caused the catastrophe, and the surviving scientists, including Shizuma, fled, allowing the world to believe that von Fogler was solely responsible. This secret has eaten away at him, and he shows clear signs of a nervous breakdown, experiencing frequent visions and hallucinations of the deceased Dr. von Fogler.

Throughout the main events of the story, Dr. Shizuma is a man on the run, desperately trying to escape from the terrorist organization Big Fire, which is pursuing him for the black attache case he carries. This case contains one of the original, unstable prototype Shizuma Drives that caused the original tragedy. His primary motivation shifts from simple survival to a final attempt at atonement. Plagued by guilt after learning that his three fellow doctors have been murdered by Big Fire, he eventually resolves to reveal the full truth of his role in the Vashtal incident to the world. In a desperate act of penance, he deliberately activates the anti-Shizuma Drive prototype he was protecting. This act demonstrates the device's terrifying power, which neutralizes all standard Shizuma Drives in the vicinity, causing a massive blackout.

His most significant relationship is with the memory of his former colleague, Dr. Franken von Fogler. This relationship is not one of connection but of consuming guilt and paranoia, as Shizuma believes von Fogler has returned from the dead to exact revenge on him and his former team. The other key relationship is with the International Police Organization's Experts of Justice, who rescue him and attempt to protect him. In the end, he confesses the secret of Giant Robo's power source to the young protagonist Daisaku Kusama, revealing that the giant robot is not powered by a Shizuma Drive but by an older, nuclear reactor.

Dr. Shizuma undergoes a significant but tragic development. He begins as a respected but fearful hero hiding a dark secret. As the story progresses, his psychological torment intensifies to an unmanageable level, shattering his will to preserve his reputation. He ultimately achieves a form of redemption by sacrificing his good name to expose the danger of the anti-Shizuma Drive and by revealing the truth about his own past crimes and the true nature of Giant Robo. He is shot by a member of Big Fire during his confession and dies shortly after, with his final words being an expression of hope as he acknowledges the potential of Robo's nuclear power. His primary notable ability is his scientific genius, specifically in the field of energy production, which led to the creation of the Shizuma Drive that defines the world's technological landscape.