This story takes place a very, very, very long time ago, when the planet we live on followed an orbit unlike its present one. Of course, it was not in its current position, either.
To put it in modern terms, back then Earth was the sun's only satellite, revolving around it with its northern half facing inward and its southern half facing outward, day after day in an unchanging cycle.
As a result, the entire Northern Hemisphere was bathed in sunlight all year round, with no night, while the Southern Hemisphere was the opposite, without sunlight throughout the year.
Over time, two races evolved on this planet: the short-lived and the long-lived.
The short-lived, who lived in the Northern Hemisphere, were humans like us. They enjoyed warmth and light, but had very short lives. The long-lived, by contrast, lived in the Southern Hemisphere, an undying race dwelling in cold and darkness all day long.
The long-lived included many kinds of beings, such as monsters, demons, ghosts, elves, vampires, and others. They were collectively known as the long-lived.
The long-lived were all incredibly powerful, possessing abilities humans did not. Compared with them, humans were as fragile as ants. But there was one thing they feared: sunlight. So no matter how vicious and terrifying they were, they posed no real threat.
In those days, the short-lived and the long-lived existed side by side.
But existing side by side did not mean they could coexist.
