a world divided by two clan which is white clan and dark clan. both of the clan fighting for a years but in 1980 everything change with a long time period of war between white clan and dark clan, the member of white clan is all human meanwhile the dark clan is all monster. in the end war stopped by two creatures they called themselve king of humanity and demon king both of them create a sacred wall to divide two clan. but then it is not enough to make a peaceful world then king of humanity divide the white clan to 3 layer and demon king divide dark clan to 7 layer it is because the demon nature is to fight and kill. demon king and king of humanity make sure to create 3 knight at the end of the world to both clan. knight is the one who will maintain the peace of the world they make the knight to make sure there will be no war anymore when both of them died. in 1990 demon king and king of humanity die and white clan begin to develop more further with magic and vast of knowledge meanwhile the dark clan begin more stronger. but in the end the grudge between two clan never can be resolved.