The Steel Sea area of ??Gransta was once ruled by one of the heroes who sealed the devil called “White Disaster”, the magician Kelegorm. Under the rule of Keregorum, countries around the steel sea flourish through the steel trade, and have long enjoyed peace and prosperity.

However, 200 years have passed since the battle with the “White Disaster”, and when the battle was about to become a legend, Kelegorm suddenly lost its cause. Immediately after the disappearance of Keregorum, a large number of monsters appear in the Steel Sea area, and the area around the Steel Sea is again confused. Many humans enter the mage's tower to get clues to the lost mage, but no one has returned safely...