In the classroom, a professor specializing in research on the Otherworld Creatures held forth at the lectern.
"To this day, humanity's knowledge of the Otherworld remains quite limited. Our exploration of it has barely scratched the surface, and most of its regions are still shrouded in mist.
"Of course, there are many reasons for this. For one thing, the number of martial artists among humanity is limited.
"Out of the world's seven billion people, there are only about two hundred thousand martial artists. That works out to one martial artist for every thirty thousand people. Registered explorers are even fewer, at around fifty thousand.
"Yet the number of Space Channels, large and small, discovered around the globe has already exceeded roughly five hundred thousand, and continues to grow. With only fifty thousand explorers spread across five hundred thousand Space Channels, humanity simply can't concentrate its forces and cultivate the land thoroughly.
"Another reason is that the Otherworld is quite dangerous. According to information gathered from around the world, humanity has discovered more than three thousand intelligent species. The barbarians are merely the most numerous and widespread, and the least threatening to humanity.
"Some species are scarce, but pose a far greater threat to humanity than the barbarians.
"In 2005, an Extraordinary Creature that briefly invaded Aoya Country and was dubbed the Hill Giant by the international community stood sixty meters tall. Just the wind from one of its punches sent armored vehicles tumbling in every direction. Armor-piercing shells from heavy cannons could only wound it, not kill it outright."
"Was it ever killed?" a martial artist asked curiously.
"No. It was an intelligent creature, after all. As soon as it saw things weren't going its way, it fled back to the Otherworld."
The professor picked up his thermos and took