At the close of the 20th century... A large-scale natural disaster struck the eastern area of a certain country. The disaster wiped out the financial sector and toppled high-rise buildings over a wide area, even as far as the main functions of the capital. This resulted in the loss of a staggering 158,000 lives.

At the dawn of the 21st century... Conglomerate PROBE-NEXUS, commonly known as Probe, begins reconstruction efforts in the eastern area of said country. Probe relocates its own base of operations to the ruined sector and builds a massive city run by the corporation. Lavished with colossal capital and cutting-edge technology, modern-day Babylon is made up of skyscrapers that put the old high-rises to shame, the biggest shopping mall in the world, and recreational facilities one might mistake for a theme park. This was the dazzling birth of a symbol for the new century. It became the most essential place on the planet and was christened Zone Prime.

Sprache; Japanese, English, Spanish, Portuguese, Italian, German, French, Simplified Chinese, Traditional Chinese, Korean