Sword princess Aiz Wallenstein. Today, once again, the strongest female swordsman heads to the giant labyrinth known as the "Dungeon" along with her allies. On the 50th floor where mysteries and threats such as a decayed dragon's corpse that crumbles to ash and an irregularity that creeps ever closer to the party loom, Aiz calls for the wind and heads deeper into the darkness of the Dungeon. Eventually, she finds herself meeting a boy for the first time. In the Labyrinth City of Orario, the contrasting stories of the boy and the girl intersect.