In 2014, a group of scientists began what is known as The Gear Project, dedicated to genetically engineering and strengthening various lifeforms on Earth through the use of Magic. It was said to be a failure and the idea was scrapped, but in 2073 it was restarted and the group created their first perfect Gear a year later: Justice. This only led to the creation of more and more Gears, including humans who had been converted into them as well as the complete Gears.

Late 2074, the Gears rebelled against humanity under orders of Justice and destroyed Japan, leading into a war lasting over a hundred years.