Noir—a name that strikes fear in the hearts of those who know the history behind the moniker. Long ago it was the code name of a very successful and feared assassin and now it is being used by two women who want answers to questions they have about their lives.

The main character in this series is a highly skilled assassin named Mireille Bouquet who is based out of France. One day, she receives a mysterious email from a girl named Kirika. Following up on the message, Mireille goes to meet this girl and discovers that not only does the girl have no idea who she really is, but she also has no idea why she is so skilled at killing people and why she feels no remorse when she does. Realizing that their lives are linked somehow, Mireille and Kirika team up and begin traveling the world together as they seek out the answers to their shared histories, while avoiding the grip of an organization known as Les Soldats. Will the two find the answers they are looking for? And will that truth free them, or ruin them?