Arcadia

Arcadia was a major human settlement following the Magical Beast invasion of Japan. It was regarded by many as Japan's last safe haven before its destruction at the hands of the First Knight.

History
Arcadia was just a normal settlement like any other that tried to survive following Japan's fall. One day, rumors spread around that other countries had created warriors called Knights that used magic to combat the magical beasts. Whether or not they believed it, the people of Japan was desperate for a solution.

Arcadia's top scientists, amongst them being Akira Nishino and Yuka's husband studied magic and succeeded when Akane became a Knight. Akane cut down the beasts that roamed Arcadia's territory. Ever since then, Japan praised Arcadia for their breakthrough. Scholars travelled there, other humans joined Arcadia to become knights and refugees found a safe heaven from the monsters.

Ironically, Arcadia's fall was not at the hands of the magical beasts but the First Knight that defended them. While Akane was powerful, she had trouble with her abilities. This dissatisfied Akira who decided to harvest the blood of magical beasts and injected it into his sister out of complete arrogance that he had control over this forbidden power. This backfired horribly as the new power within Akane caused her to go on a rampage and destroyed Arcadia, killing many people, including Yuka's husband.

With Arcadia gone, all hope was destroyed and the unity the people of Japan had was shattered.