Since the beginning of history, there were Guardian Monsters hiding between layers of time.
They are symbols of water, protecting buildings and towns from fire hazard. Our ancestors gave thanks to the Guardian Monsters and there was a harmony. However, there were people with bad intentions and the monsters got angry. They kidnapped people with bad intentions, and tortured them with endless riddles in their labyrinth. They were not allowed to escape until they solved all the problems. But once they were released, they became humble people with good hearts. Guardian Monsters are keeping balance of this world, protecting us from bad influences and rewarding the good ones, even today.