[Kira is quiet for a few moments as he tries to figure out how to say it.]
Where I'm from, in the past century humans learned how to genetically modify people - to make them stronger, more resistant to diseases, and learn things more quickly, among other things. The people who have been modified are called Coordinators.
But... some Naturals - that is, people who haven't had their genes changed - don't trust Coordinators. Some of them think that they're abominations, or not even human. There was a lot of violence, so... many Coordinators moved to the PLANTs where they felt they'd be safer. There are some still on Earth, of course, because I mean, not every Natural is like that. I don't even think most are. And there are some Naturals who live in the PLANTs.
So a lot of Coordinators don't think of Earth as their home anymore. They don't feel safe around Naturals.