Arisawa Kei’s life seems rather bleak until she notices a strange man staring at her on the way to school. Hakamada Ryuuhei, an En specialist who can see and tie or cut threads of fate, tells her that she has “death-bringer” threads on her hands. But what does that mean to Kei, who doesn’t believe in En or luck?

Sold into a king's harem, the slave Adele learns that she has become the property of a man rumored to be so cruel that he executes his female slaves after they spend a single night with him. Determined to learn the truth, the brave young woman volunteers to be the next one taken to his bed. Is the man truly a murderer, or is there another reason that so many young women have disappeared from the palace?