In an imaginary world similar to medieval Europe, humans have long been preyed on by monsters called "demon". In order to fight them, a mysterious organization merged the flesh and blood of demons with humans to create half-human, half-demon warriors. These warriors are usually women, with silver pupils and extraordinary fighting prowess, but they are also feared and rejected by ordinary people.
The protagonist Claire embarks on a journey for revenge. In the process, she meets her companions, uncovers the dark secrets behind the organization, and gradually becomes involved in conflicts concerning the survival of the world.
