It is the Middle Ages, and the remnants of mankind are plagued by death. Spoken in fearful whispers, the word "Yoma" cuts a clear image into all their minds: monstrous beings with an insatiable hunger for human flesh. There are few means to kill a Yoma. The Organization, informally known as "Claymore" (from the weapons they carry) is humanity's only line of defense that dispatches half human half Yoma female warriors to purify villages of Yoma. The main story follows low-ranking and stoic Clare.