According to ancient documents, Amboulid seems to be a floating city.
Sakura Year 16956 Capital of Humanity Qatar
"It is now nine-thirty on December 24, 16956, Year of the Cherry Blossoms. It is the first Christmas after mankind has experienced the apocalypse. In the past year, mankind has lost ninety-eight percent (choking) nine-point-eight percent of its companions..."
It's really insignificant, but things have happened and we should accept the reality.
Twelve months ago, at midnight on December 24th, Year 16955, the world was destroyed.
To be precise, the human world.
Speaking of the reason for the destruction of the world, it is related to another race opposite to humans-the vampire race.
The story begins from here!