In a world constantly haunted by demonic predators known as "Youma", the everyday life of humans is full of fear and suspicion, as these monsters easily blend into human society to hunt their hapless prey. However, in this world, there is also a mysterious organization, employing half-human, half-Youma warriors to effectively track down and kill the demons. Called "silver eyed witches" or "Claymores" after the huge Claymore swords they carry, these female warriors are eyed with suspicion and distrust by most because of their inhuman powers.

When the young boy Raki meets Clare, a Claymore sent to kill the Youma haunting his hometown, he is eventually caught in a story of love, revenge and treachery, as Clare's past meets with her future...