World War III erupted on October 15th, 1990, resulting in the annihilation of industrial establishments within a mere 40 minutes. The detonation of 1000 megatons of nuclear weapons led to a nuclear winter that engulfed the Earth for six months, killing all grain plants. Governments worldwide lost control, sending transport and communication networks into disarray. A series of state declarations emerged, with citizens establishing their own authority. America splintered into six parts, forming over twenty countries, including smaller unauthorized states.
Fast-forward to 2021, 31 years post the catastrophic war, and we meet Filicia Epstein, a bionics mastermind, who seek out Sabano. Sergeant Mutou failed to overlook Epstein's safety during her trip. In her search for her missing brother, Lyon, Epstein stumbled upon 1019, a cybernoid that led them to a hidden haven, named OZ, built by Lyon. Finally, as the story unfolds, the characters uncover the real secrets behind OZ.