After encountering the man who killed their parents ten years prior, Elmia, a priestess; and Alan, her brother and protector, set out to avenge their deaths as they fight to stem the tide of monsters flooding into the upper world, and restore peace to Alvastia.

However, in their quest to amass an army of diverse companions with the same goal, will they really be able to gain the strength necessary to bring their parents' killer to justice, and save the world...?