In celebration of the 45th anniversary of the classic Mazinger Z series, a decade has passed since humanity narrowly escaped the clutches of the villainous Dr. Hell and his malevolent underground empire. Led by Kouji Kabuto and his mighty Mazinger Z robot, the team at the photon power laboratory thwarted Dr. Hell's wicked schemes, restoring peace to the world. Now, ten years later, Kouji follows in the footsteps of his father and grandfather as a scientist. During an expedition beneath Mt. Fuji, he stumbles upon a mysterious life form within a colossal structure. A new encounter unveils a fresh threat and an uncertain destiny for humanity. As a former hero, Kouji faces a pivotal decision for the world's future, where he must embrace either divine or malevolent forces. Once more, the fate of humanity rests on the legendary Mazinger Z.