Ayumu Narumi's older brother Kiyotaka disappeared two years ago. Ayumu's only clue is "Blade Children". Now he's in high school and he's engaged in solving murders and incidents. They all seem to relate to the Blade Children. He works together with Hiyono Yuizaki, a journalist from his school. His sister-in-law, Madoka also teams up with him. They're trying to find out the Blade Children's scheme and aim. The blade children are cursed. They are notable by their cat-like eyes and by missing the seventh right rib bone. Ayumu examines and meets the Blade Children. There are five of them; Kousuke Asazuki, Rio Takeuchi, Eyes Rutherford, Ryoko Takamachi, and Kanone Hilbert. Ayumu has what he takes to save the Blade Children.