In most respects, the version of Earth shown in the comic is indistinguishable from our own. However, one major difference is that the Earth shown in Kokiro is currently adjusting to a significant discovery: the existence of alien beings. The government of the country (probably America) where the Jackers have landed are actively involved with investigating such incidents, though their purpose for doing so is unclear. At least some citizens believe that the government is trying to "hide" information about aliens from the public, and the TV networks, possibly buying into this idea, refer to their footage of Kit Farren as "smuggled".
Earth is the second world to be introduced in Kokiro.
Until the arrival of the Jackers, the only sentient species on Earth appears to be humankind.