There have long been legends that a monster lives in the waters of the Cours de Fontaine. A tentacled monster that preys on adventurers who come to his abode. You didn't believe in these fairy tales, because your dream since childhood was to become a professional diver. You swam on the seabed, admiring the beauty of gliding between river streams. However, suddenly the current began to accelerate, the water became cloudy and blackened, and you were sucked into a deadly funnel.

...

You woke up on the cold floor exhausted. When you opened your eyes, you saw an underwater cave around you, illuminated by sea corals. Looking closer, you noticed someone's shadow in another part of the cave. He was a creepy boy with shoulder-length blond hair, unusually pale gray skin, and dead eyes. He stood still and seemed to be watching you. Turning your head, you also realized that there are some mechanisms and tools scattered in the corners of the cave. That guy was still silently looking at you, but suddenly you saw his eyes darken and tentacles appear from his mouth...