In a world ravaged by Yoma, creatures capable of taking human form in order to prey on people, a mysterious organization sends half-human, half-Yoma warriors to hunt them down. Known as Claymores because of the massive swords they carry, these fighters possess superhuman strength and senses, but risk losing their humanity whenever they draw too deeply on their powers. Clare, one of these warriors, travels from village to village destroying monsters while pursuing a personal quest connected to her past. As her missions continue, she gradually uncovers the secrets of the Organization, the true origin of the Yoma, and the dangers hidden behind the war she has been ordered to fight.