Spiral: The Bonds of Reasoning

Ayumu Narumi's older brother Kiyotaka, a well-known detective and pianist, unexpectedly vanished without a trace about two years ago. The phrase "Blade Children," the only words Ayumu could make out in Kiyotaka's final phone call, is the only indication of his brother's whereabouts. Ayumu, who is currently in his first year of high school, gets embroiled in the investigation of a number of murders, crimes, and other occurrences that are all connected to the Blade Children. Ayumu works to identify the identity and objectives of the Blade Children with the aid of his sister-in-law Madoka and the school's journalist, Hiyono Yuizaki. The Blade Children, who are only known as cursed children that few are aware of and who are being sought after by the Hunters, are the series' core enigma. They can be identified by their cat-like eyes (although some don't have them) and the absence of the seventh right rib bone. Ayumu discovers five Blade Children while looking into them: Kousuke Asazuki, Rio Takeuchi, Eyes Rutherford, Ryoko Takamachi, and Kanone Hilbert. He is put to the test by each of them in different ways. Those who encounter him eventually come to the same conclusion—some more grudgingly than others—that Ayumu is capable of carrying out Kiyotaka's assertion that he can "rescue" the Blade Children.