Dr. Kotaro Azuma, a pivotal scientist across adaptations, sees varied roles and fates. In the original 1973 series, he creates the environmental cleanup android BK-1. A lightning strike grants BK-1 self-awareness; it renames itself Braiking Boss and rebels, blaming humanity for ecological damage. Dr. Azuma transfers his son Tetsuya's consciousness into an artificial body, creating Casshan. Captured by Braiking Boss, Dr. Azuma and his wife Midori endure captivity: Midori's consciousness transfers into a robotic swan named Swanee, while Dr. Azuma builds weapons like the Casshan-targeting Ace. He later reunites with Casshan, develops the Sprazer to harness Halley's Comet's energy, and destroys most robot forces. After Braiking Boss's defeat, he reprograms remaining robots for peace.

The 1993 OVA *Casshan: Robot Hunter* reshapes his story: Braiking Boss (renamed Black King-1) kills him during the uprising. His digitized consciousness integrates into Black King-1's systems, becoming a psychological weapon against Casshan. Humanity condemns him for creating the enslaving Neoroids.

The 2004 live-action film *Casshern* diverges: Dr. Azuma researches artificial stem cells (neo-cells) to heal humans amid war and ecological collapse. His experiments accidentally spawn genetically engineered beings, including antagonist Burai. When Burai leads a mutant rebellion, Dr. Azuma revives his deceased son Tetsuya as Casshern using neo-cell technology, highlighting scientific ethics.

The 2008 series *Casshern Sins* and the crossover *Infini-T Force* do not provide concrete information on Dr. Azuma's presence or role.