Haga and Amano separated from Nikola and the rest of the team, bringing the dissociated-state Sumida with them. On their quest for the rare ore, Orichalcum, they find themselves trapped in quicksand and dropped into an underground dungeon. There, they meet a woman in the tamer class and a handful of last dungeon monsters! Now Haga and Amano will have to face off with some of the strongest monsters in the game…