So it’s surprisingly difficult to find details on the more minor races and locations in The Neverending Story. There are 3 places that are referenced in Little Busters! Chapter 23 is called The City of the Old Emperors and details two of them: The city of the Old Emperors; and Basketville, the village of the Yskálnari. Chapter 25 then introduces the Minroud Mine.
Old Emperors - So in Fantastica(not Fantasia), humans from Earth have the ability to manifest their wishes through a magic amulet. Using the amulet costs a piece of your memory, and the amulet only works as long as you have memories of Earth. The Old Emperors are humans that got trapped in Fantastica and ended up forgetting all about themselves; they also get called the Know Nothings. They are just kinda zombies that do human-like activities on auto pilot.
“These people here used up all their memories. Without a past you can’t have a future. That’s why they don’t get older. Just look at them. Would you believe that some of them have been here a thousand years and more? But they stay just as they are. Nothing can change for them, because they themselves can’t change anymore.”
Yskálnari - Basketville is a community where everything is the same. All buildings, items, clothes, etc. are made from the same straw material. Its recidents, the Yskálnari, are all in agreement and always operate in groups. They are all conjoined mentally, and there’s no individuality. Below is what happens when a large crow grabs and eats one of them.
When the danger was past, the sailors emerged and resumed their song and dance, as though nothing had happened. Their harmony was undisturbed, and far from grieving, they didn’t waste so much as a word on the incident.
“Why should we grieve?” said one of them when Bastian inquired. “None of us is missing.”
With them the individual counted for nothing. No one was irreplaceable, because they drew no distinction between one man and another.
This is what Kanata refers to when she talks about students leaving and how it’s easier to leave when no one gets emotional about it.
Minroud Mine - When humans on Earth dream up something but forget it when they wake up, that dream has to go somewhere. Those dreams are manifested in the ground of Fantastica. Minroud is the place where Yor the blind miner digs up dreams from the depths. Dreams take the form of fragile, paper-thin pieces of isinglass.
Minroud is the namesake of the ZEN manga adaptation of Kanata’s route. I’m not sure if it’s mentioned anywhere else.