Due to nuclear pollution in 2109
Animals and plants of the world...
Everything has changed
Humanity evolved sentries, guides and ordinary people
At the same time, because of the disappearance of Siren
The sea begins to stir
The tsunami submerged 60% of the land
Humanity has established four major bases
Under the four major bases, there are eight special zones
Established research institute
Research Artificial Creation of Sentinel Guides
Known in history as the "Tide Era"
Concept: the product of sudden whims