Toono Shiki was involved in a major accident in his childhood. He was so severely injured that people thought he was dead, but he miraculously survived. However, due to that incident, Shiki is sent away from the Toono household and put into the care of a distant relative's family.Ever since the accident Shiki has changed. He now sees lines at which things and living beings completely "break" when stabbed with a blade. Troubled by this ability, young Shiki is given a pair of glasses by a women he calls Teacher, which stop the "lines of death" from being seen. Thanks to this, Shiki was able to live normally up until now.But then he receives a sobering letter. The head of the Toono household — his father's household — has died. By orders of the new head of the household, he must return at once to the Toono house.Shiki, now a high school student, thus returns to the Toono household, where all does not seem to be right...