'In 1242, it was not humans who stopped the advance of the Mongolian army.'

Mongolian army that swept through Eastern Europe and created a bloodbath.
Only ruins remain where they reach.
Because of the blood that so many victims shed
A completely unexpected being wakes up...…

The Mongolian commander-in-chief, Subutai, is desperate.
He orders a group of hunters to hunt down the unknown.

But they don't know that this was the beginning of a long war
between humanity and the unknown. ......

The story of the beginning of the Anemia universe.