2037 AD, A massive meteor shower fell from the sky and brought all known human civilization to an end.

Years later, inside Hong Kong's enormous crater, some surviving scientists discovered a large meteorite hovering in the air. From the mysterious meteorite, dubbed "Zero Metal", the scientists were able to extract the enormous energy that they desperately needed. The incredible finding led to the building of a massive life support system. The news traveled quickly and survivors flocked to the crater. Millions of refugees quickly depleted the limited resources, and stretched the life support system to the breaking point. Eventually the Neo Hong Kong island blocked off its borders and no new refugees were allowed to set foot.

2067 Neo Hong Kong island founded the "Gang Dao" Government body. A police force equipped with the Z.M.D.C. armor was assembled to execute the will of the new government.

Angered and fearful, refugees outside of the walled city of "Gang Do" band together to fight for their own survival.