The Zone of the Enders series is set in the late 22nd century. Humankind has colonized Mars, and space colonies are also set up in orbit around Jupiter. Fueling this expansion are two scientific advances: the development of the Laborious Extra-Orbital Vehicle, or LEV, a mecha used for labor and military use, and the discovery of Metatron, a high-energy ore found on Callisto.
However, those in power on Earth begin to take a dim view of the colonists of Mars and Jupiter, calling them "Enders", and imposing harsh and exploitive laws and taxes against them. Eventually, different groups on Mars begin to rise up in opposition to Earth. A new weapon given to these rebels is the Orbital Frame, a mecha making extensive use of Metatron-based technology, These Orbital Frames come to shape the destiny of Earth and its colonies, for both good and evil.