In the game's backstory, global warming has caused worldwide flooding, leaving much of the world uninhabitable. This forced the governments to build new cities above the waterline, using the ruined cities as foundations.[2] Since much of the world's population had died during the climate crisis, robots were used as the main labor force. An American-based company called Bergen controlled a very large majority of the world's robotic industries, making America much more powerful. A Japanese corporation named Amada tried to sue Bergen for stealing their technology in a patent dispute. Despite the fact that Amada was the first robotics company to create a humanoid robot,[3] the lawsuit failed, since Bergen had a great amount of influence.[2] This resulted in Bergen controlling 95 percent of the robotics market.[3]
World economic concerns lead to the creation of the "New Geneva Convention", a new set of international laws. One of the clauses outlined, Clause 21, banned research into robots that could pass for humans, called "Hollow Children" in the game.[4][5] A majority of the world's countries agreed to sign the convention into law.[2] An organization called the International Robotics Technology Association (IRTA) created a global task-force, nicknamed "Rust Crews", to deal with breaches of the convention.[6]
Years after the treaty was signed, an android (a "Hollow Child") attacked Bergen's headquarters in Detroit, Michigan, previously having no idea that he was a robot himself.[4] Believing that robotics genius and founder of Amada corporation, Yoji Amada, created the robot, the IRTA sent one of their Rust Crews to Japan to find Amada and bring him in for questioning under orders from the UN Security Council.[7][8] This starts the game with the Rust Crew entering Tokyo via the seawall which has become necessary due to sea rise. The game follows the Rust Crew as they fight their way through Tokyo, slowly unravelling the story behind Bergen, Amada and the "Hollow Children".
