[ReddyRedWolf]

Originally Posted by Kaoru Chujo

Spoiler for ep1:

Are Aoi's apparent special powers just technology, and are various aliens fighting a war on Earth? Or are all the aliens actually from Earth? Two planets are unlikely to speak the same language. One possibility: time travel.

Well Eris did say their planet is also called Earth, in the process of renaming it to avoid confusion, and they surprised also of humans appearance that thought it was a hoax at first.