Between 2021 and 3053, a string of catastrophic events decreased the world's population to a measly 10%. All of the known cities and continents cease to exist in the present day, about 21 new cities were built on the new and only continent Fremavia. Monsters are known as Demon beasts who now roam the land there are many different types of them some strong some weak, some intelligent some not, some humongous, and some microscopic. But out of all of them, 4 demon beasts stand heads and shoulders above the rest the nine-tailed firefox Azure, the rhinoceros beast with a skin made of metal and earth Machia the sea serpent Boa and the ruler of the sky Minokawa.