Claymore started out, as a lot of anime does, as a manga.
This dark fantasy manga series written and illustrated by Norihiro Yagi. It appeared in the Monthly Shōnen Jump in May 2001.
When Monthly was canceled in June 2007, the series moved to Weekly Shonen Jump.
The first eleven volumes of the series was made into a twenty-six episode anime series by Madhouse Studios, and it premiered in Japan on NTV on April 3, 2007.
The plot is basically that a group of superhuman warriors called Claymores are created by a nameless secret organization to protect humans from flesh-eating creatures called Yoma.
Most of the claymores are female, because human males who are changed to hybrids (by implanting Yoma flesh and blood into humans) tend to lose control of their powers faster.
The series follows the adventures of one Claymore named Clare and her friend Raki.
