The manga takes the work of Isao Miura, telling the story of a young knight, Cecily Campbell, wanting to get a katana in a world where "demonic pacts" or demons are devastates everything.
Formerly, the continent was ravaged by a terrible war where the "demonic pacts" were in common place. Forty-four years later, Cecily Campbell, a descendant of former nobles and members of a company of knights, is looking for a blacksmith that can repair her old sword that already blunted. Her path crosses that of Luke Ainsworth, a young man who brings down a once a vagabond in the grip of a demonic pact.