A grand and magnificent castle towers over the Central Plains of the Continent of Astral. This is the castle of the brave hero Kaizer who bore the title of "Grand Master." He was the one who sealed the Devil known as Dante and brought peace to the whole world. But when Dante came back to life, the seal weakened. For starters, the Devil obliterated all the humans inside the castle and populated it with monsters. They say the monster that abducted Siren is inside this castle too. Without having a clue as to Dante's whereabouts, Rody went to the Kaizer Castle in search of a mere trace.