Spiral: The Bonds of Reasoning (manga)

In Spiral, Ayumu Narumi is a teenage boy who is accused of murdering Sayoko Shiratanagi. His sister-in-law is the one who is in control of the case, so she lets him go. Ayumu is determined to find the answer to the mystery, and, along with the head of the newspaper, Hiyono, figures it out. This sets off a series of events. He meets pianist Eyes Rutherford, Rio Takeuchi, Kosuke, Ryoko, and their so called leader, Kanone. For some reason, they all seem to know his older brother, Kiyotaka, and they think that he can save them. Just who are the "Blade Children". 

Two years ago, the famous detective Narumi Kiyotaka disappeared, leaving behind only the words, "I am pursuing the mystery of the Blade Children." Now, his younger brother Ayumu is accused of murdering a fellow student, and begins to discover people with connections to the Blade Children all around him. The Blade Children were born cursed, and Ayumu may be the only key to saving them, but first they want to test him, by trying to kill him with everything they've got. All the while, it seems that Kiyotaka is manipulating events for his own unknown purposes.