In the futuristic setting of U.C. 0123, the Earth Federation Forces have developed the F91 Gundam, a cutting-edge mobile suit equipped with a Bio-Computer. Dr. Monica Arno and her team work tirelessly to overcome the F91's instability issues. Meanwhile, a mysterious organization called the Crossbone Vanguard emerges, led by Iron Mask and Supreme Commander Meitzer, with ambitious plans to change the world.