From the web page:
This...role-playing game is set in the world of Masamune Shirow's classic cyberpunk series Appleseed, one of the best manga series ever to be translated into English.
The events of Appleseed take place after a great world war. Though nuclear weapons were never used, massive biological weapons were let loose upon the world. Advanced technologies were used to destroy most centers of civilization. As the old nations attempt to rebuild, a new power, called Olympus, stands out as the most technologically advanced and civilized nation on the planet.