The Blade Children (Spiral: The Bonds of Reasoning)

Eyes Rutherford (アイズ・ラザフォード?)
A 17-year-old world-class pianist, he is second only to Kiyotaka Narumi, Ayumu Narumi's older brother. He is seemingly cold-hearted but definitely not heartless (he brought Rio melons when she was stuck in the hospital). Eyes is quarter English and debuted in the musical world at the age of 14. He cares a great deal about the Blade Children and would do anything for them to survive at all costs. He is exceedingly loyal to Kiyotaka's words and seems to believe in Ayumu the most out of all the Blade Children. Eyes knows much more than the other Blade Children do, holding secrets he keeps to himself. He is one of the first targets of assassination by the Hunters (after Sayoko Shiranagatani) but outwits them at a charity concert with the help of Ayumu and Kousuke Asazuki. He and Kanone Hilbert have a some sort of bond, even though the friendship between Eyes and Kanone seems to shatter once he learned of Kanone's betrayal of the Blade Children. Eyes appears to be the leader of the Blade Children but he treats Kanone as either an equal or even an older brother. Eyes and Kanone are revealed to be half-brothers in chapter 36 of the manga, and later it is revealed that all of the Blade Children are half siblings, for they share the same father.
In the end he concentrates on his piano skills, known as the "savior of the music world." This is the path he chose to create hope for himself.
Voiced by: Akira Ishida (Japanese), John Burgmeier (English)

Kousuke Asazuki (浅月香介 Asazuki Kōsuke?)
The most arrogant, aggressive and most violent of all the Blade Children, Kousuke is usually the implementor of assassinations. Kousuke is very strong-willed and stubborn, choosing to fight the Hunters head-on rather than hide from them. He is not afraid to kill and does not really trust Eyes, resulting in arguments between them. It is revealed by Hiyono Yuizaki after his challenge with Ayumu Narumi that Kousuke's mother died in a car accident when he was 3, leaving him orphaned. While Rio Takeuchi calls him stupid, in reality Kousuke is very intelligent; after skipping most of elementary school, he still manages to catch up to secondary school level from reading and learning from books. Kousuke left middle school after a run-in with a teacher. He is a childhood friend of Ryoko Takamachi and harbors deep feelings for her as he goes out of his way to protect her (even jumping into a bear pit she had fallen into to save her.) Kousuke's astrological sign is Virgo.
The final path Kousuke chose is "ordinary," in that he goes to college with Ryoko. He becomes the main character in the spin-off, Spiral Alive.
Voiced by: Takeshi Kusao (Japanese), Greg Ayres (English)

Rio Takeuchi (竹内理緒 Takeuchi Rio?)
The "midget" of the Blade Children, she resembles a 13-year-old child rather than her actual age, 16. Although Rio appears to be the most innocent of the Blade Children with her cherubic features and size, she is actually very shrewd and calculating. Rio knows how to create bombs, devise difficult plans and kill those she considers her enemies. Kanone even calls her a "fire pixie" in the manga for her small, impish appearance and skill with explosives. She is extremely intelligent and is able to escape from any sticky situation, no matter how small or tight it is. She is very straight-forward and has a crush on Eyes because he gives her "netted pattern" melons (her favorite food). Like Kousuke, she will not hesitate to kill people if she has to.
The path Rio takes is working in third-world countries, defusing land mines left over from war.
Voiced by: Yui Horie (Japanese), Monica Rial (English)

Ryoko Takamachi (高町亮子 Takamichi Ryōko?)
One of the most down-to-earth members of the Blade Children; Ryoko is a clever and athletic person, probably the most athletic of the Blade Children. She is a natural-born runner and can outrace almost anyone. She is a childhood friend of Kousuke Asazuki and, unlike the other Blade Children, she despises killing. She dislikes Eyes Rutherford due to past issues and cares deeply for Kousuke, though she has a tendency to use him as a punching bag and make him buy her food. Her past is relatively unknown, though it is hinted that something traumatizing happened while Kousuke and Eyes were present. She is reluctantly brought back into the conflict of the Blade Children by Eyes after losing to him in a simple game of dodge ball. She honours their deal to join with the rest of the Blade Children, with only one condition: she will not kill anyone.
The manga reveals that Ryoko is capable to using a gun like the other Blade Children, though she dislikes using one. She is shown to have a strong intuition, being able to determine that Kanone would attempt to kill Rio. Ryoko's apparent feelings for Kousuke are also made more explicit in the manga. She blushes and cries as she hugs him after he wakes from a brief coma and becomes incredibly jealous of Rio when Kousuke stands up for her.
She is still with Kousuke and hopes to run in the Olympics.
Voiced by: Hitomi Kato (Japanese), Laura Bailey (English)

Kanone Hilbert (カノン・ヒルベルト?)
A Blade Child with a dual personality. He can be cute and friendly or manipulative and insane. He was very close to Eyes. He would cry for Eyes when Eyes could not when they were young, but their friendship fell apart as they grew older and developed vastly different opinions on the fate of the Blade Children. Hiyono Yuizaki confronts Kanone right before Eyes is shown to have woken up, revealing that Kanone is a Libra, born on September 25. He is 17 years old, blood type A. She also knew his favorite food, which is banana bean jam.
In the manga, it also mentions that Kanone and Eyes are "brothers". Kanone will go as far as he can to kill the people who give the Blade Children false hope, to prove to Eyes and the Blade Children they have "no hope." He is capable of terrible things and is interested in killing Ayumu because he is the Blade Children's only hope that they can actually be saved. Kanone is even willing to work with the Hunters to prove to the Blade Children that they have no hope. In the manga, Kanone wants to kill his friends due to the fact that he fears losing them to the Hunters and would rather kill them himself, but his subconscious keeps him from killing them. Kanone, despite his lack of hesitation to kill, has vowed to himself that he would not kill innocent people, and would only kill all the people related with the Blade Children, and the Blade Children themselves. To Kanone, his actions were a form of salvation and punishment for everyone who caused the Blade Children to be born in this world.
In the manga, Kanone has incredible "killer reflexes" so that when he is attacked, or even senses danger, his body will automatically react and set himself up for battle position. Due to his powerful gift, Kanone vows to only kill the Blade Children since he does not want to lose control and go on a killing spree of innocents. These powerful traits and his vow are ultimately his downfall as Ayumu manipulates them to his advantage before hitting him with a tranquilizer.
He has a very close relationship with Eyes, since he is the only one Eyes ever called "big brother". Kanone also has a soft spot for cats, as he buys a kitty plushy in the manga and Rio suggests that they dress like kitties so he won't attack them during the school battle. Hiyono Yuizaki also revealed in her confrontation against Kanone after his attack on the girls, that his especially favorite cat are himalayan cats.
Kanone wishes for Ayumu to kill him - if Ayumu did, he could no longer be the saviour of the Blade Children. After a battle of wits and speed in Tsukiomi Academy, which spans multiple volumes, he is hit with a tranquilizer bullet and subsequently put under house arrest in a secure location. He is visited by Hizumi, and willingly gets killed by him. This is the path he chose. By killing Kanone, Hizumi's choices are severely limited, and he cannot fight his destiny. Kanone's last word to Ayumu was "Hope", asking Ayumu to have faith in his own path, for this is Ayumu's fate.
Voiced by: Kenji Nojima (Japanese), Christopher Bevins (English)

Sayoko Shiranagatani (白長谷小夜子 Shiranagatani Sayoko?)
One of the Blade Children, she was adopted and raised with the hope that she would not suffer like others like her. However, once Sayoko's identity as one of the Blade Children emerged, she is mysteriously pushed off the roof of the school (In the manga, it is Munemiya Kana that is pushed off the roof). Ayumu becomes the first suspect because he was the only one present at the roof at the time, despite the fact he is completely innocent. She survives miraculously and later recovers but suffers from amnesia, though she is happy with her current life and continues to live hopefully. In the manga, she feared something and attempted to commit suicide at age 10 after her mother died. After the attempt, she completely lost her memory. She is said to be different from the other Blade Children. Unlike the other Blade Children, she does not possess the characteristic slit-pupils and appears a lot more naive of the blade children situation.
Voiced by: Mai Nakahara (Japanese), Elise Baughman (English)