[Machine Translation] One day, Keiichi and his classmates are suddenly summoned to another world. It is a special world where women are transformed into weapons, and men who sign a contract with them can fight with them in their hands. Keiichi finds himself in a difficult situation in such a world, but what he quickly concludes a partnership contract with is not a human woman, but... a female dragon. It was a female dragon. (The dragon, who calls herself Winifried and has the two names of "Eater Dragon," transforms into a jet-black sword and a girl in a maid's outfit to become Keiichi's partner...