Spiral: The Bonds of Reasoning (Japanese: テンプレート:日本語, Spiral: Suiri no Kizuna) is a Japanese manga series written by Kyo Shirodaira and illustrated by Eita Mizuno. Initially serialized by Enix and later by Square Enix, the series ran in Monthly Shōnen Gangan from 1999 to 2005, spanning 15 tankōbon volumes. The story centers on Ayumu Narumi, a high school student, as he investigates the enigmatic Blade Children—gifted individuals with cat-like eyes and the absence of a seventh rib bone, who are said to be cursed.
A prequel, Spiral: Alive, also created by Shirodaira and Mizuno, was serialized in Gangan Wing and later Monthly Shōnen Gangan from April 2004 to June 2008, culminating in five collected volumes.
In North America, Spiral: The Bonds of Reasoning was initially licensed for English publication by Tokyopop, but the company discontinued the series. Yen Press subsequently acquired the rights and released the first volume in October 2007.
The series was adapted into a 25-episode anime television series, which aired on TV Tokyo from October 1, 2002, to March 25, 2003. The anime was licensed in Region 1 by Funimation, which distributed it on DVD and broadcast it on the Funimation Channel, as well as on the Colours TV programming block in 2006. Additionally, the franchise expanded into four light novels and a series of CD dramas.
Plot
Spiral: The Bonds of Reasoning
Two years prior to the start of the series, Ayumu Narumi’s older brother, Kiyotaka, a renowned detective and pianist, vanishes without a trace. Before disappearing, Kiyotaka makes a cryptic phone call to Ayumu, leaving him with a single clue: “Blade Children.” Now a high school freshman, Ayumu becomes entangled in a series of murders and mysterious incidents, all connected to the enigmatic Blade Children. With the help of his school’s journalist, Hiyono Yuizaki, and his sister-in-law, Madoka, Ayumu works to uncover the truth behind the Blade Children and their goals.
The Blade Children are at the heart of the mystery. They are cursed individuals pursued by the Hunters, an organization that seeks to destroy them. Identified by their cat-like eyes (though some lack this trait) and the absence of their seventh right rib, the Blade Children’s origins and purpose are shrouded in secrecy. As Ayumu interacts with five key Blade Children—Kousuke Asazuki, Rio Takeuchi, Eyes Rutherford, Ryoko Takamachi, and Kanone Hilbert—he is tested repeatedly. Over time, the Blade Children come to believe that Ayumu possesses the potential to “save” them, as Kiyotaka once predicted.
The anime adaptation follows the story up to the sixth volume of the manga, comparing the Blade Children to cuckoo birds, creatures that are left in the nests of other birds and grow increasingly dangerous with age. The manga extends the story, delving into Ayumu’s discoveries about the Blade Children’s origins, their connection to Kiyotaka, and the reasons behind Kiyotaka’s belief in Ayumu’s role as their savior.
Thirty years earlier, a man named Yaiba Mizushiro was born missing a rib on his right side, much like the Blade Children. A prodigy, Yaiba founded a secretive and powerful organization. Out of boredom, he launched the “Blade Children Project,” using his DNA to create 80 genetically modified children, each marked by the removal of a rib at birth. These Blade Children inherited Yaiba’s genius but were also cursed to one day lose their self-will and become murderous avatars of Yaiba’s ambition.
Yaiba’s organization fractured into three factions over the Blade Children:
- The Savers: Supporters of Yaiba’s goals, they sought to protect the Blade Children after Yaiba’s death.
- The Watchers: Neutral observers who aimed to study the Blade Children and their development.
- The Hunters: Opponents of Yaiba, they sought to eliminate the Blade Children to prevent their potential danger.
At 36, Yaiba was killed by Kiyotaka Narumi, who became Yaiba’s counterforce. While Yaiba sought destruction, Kiyotaka worked to preserve the balance, fighting to protect the Blade Children from the Hunters and contain the ambitions of the Savers.
Eventually, Ayumu confronts his own counterpart, Hizumi Mizushiro, Yaiba’s younger brother and the one destined to awaken the Blade Children’s violent tendencies. Through his friendship with Hizumi and growing confidence in his own abilities, Ayumu comes to embrace his role as the Blade Children’s savior, leading to a final confrontation that determines their fate.
Spiral: Alive
Spiral: Alive follows Imari Sekiguchi, a girl in love with Shirou Sawamura, an aspiring detective. Before she can confess her feelings, Shirou unexpectedly leaves school to pursue Kiyotaka Narumi. Unbeknownst to Shirou, his girlfriend, Yukine Amanae, is a reluctant murderer. As Imari and Shirou grow closer to uncovering Yukine’s secrets, they become entangled in events connected to the Blade Children.
Toru Saiki, a police investigator, begins probing a series of murders linked to Yukine but refuses to involve Kiyotaka, whom he views as a dangerous figure. The lives of Imari, Shirou, and Saiki intersect as they unravel mysteries surrounding the Blade Children and the shadowy factions pursuing them.
The series reveals that of the 80 original Blade Children, 13 have vanished from the records of the Hunters, Savers, and Watchers. These disappearances were orchestrated by a neutral party, who committed suicide after ensuring the erasure of these individuals. The only surviving record of their existence is the Mikanagi File, created by Professor Isabel Mikanagi, who masterminded their removal. After her death, the file was passed to Yukine’s parents. Following their deaths at the hands of a Hunter, Yukine became the sole bearer of the file’s secrets, stored entirely in her memory.
Returning characters from the original series include Kiyotaka, Kousuke, Ryoko, Kanone, and Madoka, further tying the prequel to the overarching mystery of the Blade Children.
Main characters
Ayumu Narumi
- The protagonist of Spiral: The Bonds of Reasoning, Ayumu is a reserved and introspective high school student with exceptional intelligence. He struggles with self-doubt, stemming from the belief that he cannot surpass his older brother, Kiyotaka, a renowned detective and pianist. Despite his insecurities, Ayumu is a skilled pianist and an excellent cook. He shares a deep bond with his sister-in-law, Madoka, and once harbored feelings for her but let them go after her marriage to Kiyotaka. Throughout the series, Ayumu is portrayed as the Blade Children’s sole hope for salvation, with Kiyotaka emphasizing that Hiyono is the most important person in Ayumu’s life.
Hiyono Yuizaki
- Hiyono is the cheerful and energetic school journalist who serves as Ayumu’s loyal sidekick. Her quick wit and resourcefulness often come in handy, though her confidence sometimes borders on arrogance. The polar opposite of Ayumu, Hiyono is extroverted and provides much of the series’ comic relief. She is a skilled hacker with access to an extensive network of resources and frequently uses blackmail to achieve her goals. Hiyono’s faith in Ayumu never wavers, and she shows unwavering loyalty and belief in his abilities. However, it is revealed later in the series that Hiyono is a spy planted by Kiyotaka to assist Ayumu. She has also lied about her age, being older than she initially claimed.
Eyes Rutherford
- Eyes is a 17-year-old world-class pianist and a member of the Blade Children. Part English, he debuted as a pianist at the age of 14 and is known for his stoic demeanor and unwavering loyalty to Kiyotaka. Eyes is deeply committed to the survival of the Blade Children, often taking on a leadership role among them. He views Ayumu as Kiyotaka’s successor and has great faith in his abilities. Eyes keeps many secrets about the Blade Children and their mysterious origins, making him a key figure in their struggle for survival.
Kanone Hilbert
- Kanone is a Blade Child with a dual personality, capable of being charming and kind but also manipulative and ruthless. Once close friends with Eyes Rutherford, their relationship soured over differing views on the Blade Children’s fate. Kanone believes their situation is hopeless and works with the Hunters to destroy those who give false hope. Over time, he regains his sanity and begins to believe in Ayumu’s potential to save the Blade Children. Tragically, Kanone is killed by Hizumi Mizushiro, but not before urging Ayumu to use his death as a turning point. Kanone is also a master fighter who trained many of the Blade Children in combat.
Hizumi Mizushiro
- Hizumi is a manga-exclusive character and the “younger brother” of Yaiba Mizushiro. He serves as Ayumu’s counterpart, embodying traits that are opposite to Ayumu’s. Charismatic and outwardly friendly, Hizumi hides his manipulative and sinister nature beneath a cheerful facade. While he initially bonds with Ayumu, Hizumi’s true personality reveals a lonely and desperate individual consumed by despair. He becomes a formidable adversary to Ayumu, representing a significant challenge in the latter part of the series. Main Characters
Ayumu Narumi
- The protagonist of Spiral: The Bonds of Reasoning, Ayumu is a reserved and introspective high school student with exceptional intelligence. He struggles with self-doubt, stemming from the belief that he cannot surpass his older brother, Kiyotaka, a renowned detective and pianist. Despite his insecurities, Ayumu is a skilled pianist and an excellent cook. He shares a deep bond with his sister-in-law, Madoka, and once harbored feelings for her but let them go after her marriage to Kiyotaka. Throughout the series, Ayumu is portrayed as the Blade Children’s sole hope for salvation, with Kiyotaka emphasizing that Hiyono is the most important person in Ayumu’s life.
Hiyono Yuizaki
- Hiyono is the cheerful and energetic school journalist who serves as Ayumu’s loyal sidekick. Her quick wit and resourcefulness often come in handy, though her confidence sometimes borders on arrogance. The polar opposite of Ayumu, Hiyono is extroverted and provides much of the series’ comic relief. She is a skilled hacker with access to an extensive network of resources and frequently uses blackmail to achieve her goals. Hiyono’s faith in Ayumu never wavers, and she shows unwavering loyalty and belief in his abilities. However, it is revealed later in the series that Hiyono is a spy planted by Kiyotaka to assist Ayumu. She has also lied about her age, being older than she initially claimed.
Eyes Rutherford
- Eyes is a 17-year-old world-class pianist and a member of the Blade Children. Part English, he debuted as a pianist at the age of 14 and is known for his stoic demeanor and unwavering loyalty to Kiyotaka. Eyes is deeply committed to the survival of the Blade Children, often taking on a leadership role among them. He views Ayumu as Kiyotaka’s successor and has great faith in his abilities. Eyes keeps many secrets about the Blade Children and their mysterious origins, making him a key figure in their struggle for survival.
Kanone Hilbert
- Kanone is a Blade Child with a dual personality, capable of being charming and kind but also manipulative and ruthless. Once close friends with Eyes Rutherford, their relationship soured over differing views on the Blade Children’s fate. Kanone believes their situation is hopeless and works with the Hunters to destroy those who give false hope. Over time, he regains his sanity and begins to believe in Ayumu’s potential to save the Blade Children. Tragically, Kanone is killed by Hizumi Mizushiro, but not before urging Ayumu to use his death as a turning point. Kanone is also a master fighter who trained many of the Blade Children in combat.
Hizumi Mizushiro
- Hizumi is a manga-exclusive character and the “younger brother” of Yaiba Mizushiro. He serves as Ayumu’s counterpart, embodying traits that are opposite to Ayumu’s. Charismatic and outwardly friendly, Hizumi hides his manipulative and sinister nature beneath a cheerful facade. While he initially bonds with Ayumu, Hizumi’s true personality reveals a lonely and desperate individual consumed by despair. He becomes a formidable adversary to Ayumu, representing a significant challenge in the latter part of the series.
Media
Manga
Spiral: The Bonds of Reasoning was serialized by Enix in Monthly Shōnen Gangan from 1999 to 2005 and was collected into 15 tankōbon volumes. Initially licensed in North America by Tokyopop in 2005, the release was canceled before publication. Yen Press later acquired the license in 2007, releasing all volumes from October 2007 to April 2011.
The prequel and spin-off series, Spiral: Alive, written by Kyo Shirodaira and illustrated by Eita Mizuno, was serialized in Gangan Wing starting May 2001. In 2006, it moved to Monthly Shōnen Gangan and concluded in June 2008. The series was collected into five tankōbon volumes.
Anime
Spiral: The Bonds of Reasoning was adapted into a 25-episode anime series by J.C.Staff, directed by Shingo Kaneko. It aired on TV Tokyo from October 1, 2002, to March 25, 2003, and covers the first six volumes of the manga, featuring an anime-original ending.
Key details about the anime include:
- Opening Theme: “Kibouhou” (“Cape of Hope”) by Strawberry Jam
- Ending Theme: “Kakuteru” (“Cocktail”) by Hysteric Blue
- Insert Song: “Twinkle My Heart” by Mitake Akira (performed by Hiyono Yuizaki)
The anime incorporates classical piano music, such as:
- “Jeux d’eau” by Maurice Ravel (Episode 3)
- “Liebestraume No. 3” by Franz Liszt (Episode 13)
- “Benediction de Dieu dans la solitude” by Franz Liszt (Episode 21)
- “Arabesque No. 1” by Claude Debussy (Episode 25)
The soundtrack, composed by Akira Mitake, was released on March 19, 2003.
The anime was licensed for North America by Funimation and released on six DVDs and as a complete box set. It was also broadcast in English on the Funimation Channel and Colours TV in 2006.
Reception
Both the manga and anime adaptations have been praised for their suspenseful storytelling and intricate mystery elements. However, the manga has received minor criticism for overt sexual content.
See also
- In/Spectre, another manga series written by Kyo Shirodaira.