Between this world and the next exists a special world. It's a dimension of life phantom in nature yet one very real. Access to it is granted only on certain occasions and the times of admission are brief windows lasting mere seconds. The stay in that world depends on how long the soul braves to stay there, because in all honesty, it is a terrifying country. It is Arco, the other world, the world of the inbetween.

On a planet much like our own, the king of a highly technological race known as the Adamah forms a pact with the faeries of the neighboring dimension; they are the Sanritem. Suspiciously, as a new ruler was crowned amongst the faeries, the king of the Adamah died, leaving orphan his two children, Myungsoo and Myungeun. Taking advantage of the fact, the new faerie king, Oscuridaon, laid siege to the Adamah world. Years after, all of the Adamah's pride and glory has been reduced to ashe