This list covers the tropes for characters in the original book series of The Ring. For their tropes as described in the Japanese adaptations, go here. For tropes related to the American film adaptations, go here.
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Introduced in Ring
Kazuyuki Asakawa
Kazuyuki Asakawa
The protagonist of Ring. Kazuyuki is a Tokyo-based journalist who investigates the death of his niece Tomoko and three other teenagers, discovering the cursed videotape's existence and seeks to end its curse. At first he is a workaholic but when his wife and daughter watch the tape, he is determined to move mountains to save them.- Author Appeal: One of the driving forces behind Asakawa's character in the novel is his relationship with his daughter. The author is a leading advocate of stronger father/daughter relationships in Japanese society.
- Badass Normal: Very determined to solve the mystery of the videotape, particularly when his wife and daughter watch it.
- Chekhov's Gun: The copy of the tape Kazuyuki made for Ryuji. He tries to use it to save his family.
- Heroic BSoD: After his family watch the tape, Ryuji dies and realising the enormity of the virus' power, and when Sadako manipulates him into writing the journal to spread the virus.
- Intrepid Reporter: Goes to great lengths to uncover the truth behind the videotape.
- Nice Job Breaking It, Hero: Kazuyuki finds Sadako's body and it gives it to her family and everything looks fine. That is until Ryuji dies of a heart attack, revealing the Ring Virus is still active and can only be stopped by copying the tape. In Spiral, it is revealed Kazuyuki wrote a journal on his investigation, thought manipulated by Sadako into doing, thus having a secondary container to spread the virus with. By the end of the novel, it has been adapted into a novel by Kazuyuki's brother, and an eventual film.
- Outliving One's Offspring: His daughter, Yoko, predeceases him by several weeks.
- Papa Wolf: Comes off as a bit of a reluctant parent, finding his daughter Yoko's constant crying to be a bother. However, as soon as he learns his family have viewed the videotape, his true devotion to his daughter comes out.
- Salaryman: A bit focused on his work and dislikes certain aspects of being a father.
- Shoot the Shaggy Dog: His whole storyline. Not only he fails to solve the ring virus before dying, he drags his whole family into the rigmarole, and unwittingly accelerates the spread of the virus.
- Sudden Sequel Death Syndrome: Kazuyuki and his family are abruptly caught in a car crash a few days after the events of the first novel. His wife and daughter die, though it is later revealed they may have died before the crash. Kazuyuki ends up in a coma for a month and eventually dies himself.
- Unwitting Instigator of Doom: As part of Sadako's plan to spread the tape.
Ryuji Takayama
Ryuji Takayama / Kaoru Futami / Seiji Kashiwada
A mathematician, philosophy university teacher, and former medical student. Ryuji is an eccentric but intelligent man who aids his friend Kazuyuki in investigating the origins of the cursed videotape. He dies in the climax of Ring to show the real nature of the ring virus, but is resurrected in Spiral, having made a deal with Sadako Yamamura to come back to life in exchange for helping her spread the virus to the whole world.In Loop, it is revealed that Ryuji was cloned by the scientists of LOOP shortly before he died, and transferred to the real world, where he grew up as a man named Kaoru Futami with no memories of his life in the artificial world. He becomes an unlikely savior of LOOP and the real world when the scientists figure out that he is immune to the effects of the Metastatic Human Cancer Virus, and returns to his home world to mass produce a vaccine, eliminating the virus for good.
In S, Ryuji took over the identity of Seiji Kashiwada, a convict accused of killing several girls who were clones of Sadako Yamamura. He is the biological father of Akane Maruyama, having fathered her with Masako, the Sadako clone born to Mai Takano.
- The Ace: Very smart and a genius in intuition, mathematics, and medicine.
- Age-Gap Romance: With Reiko Sugiura, who is fifteen years his senior.
- Amateur Sleuth: Has no background as a detective, but is bright enough to investigate the M.H.V.
- Back from the Dead: After dying, Ryuji is resurrected by Sadako and reappears as his adult self a few months after Ando makes his deal with Sadako. In Loop, it is revealed protagonist Kaoru Futami is the resurrected Ryuji. Extracted from the Loop computer system as a baby, he was raised as a normal person until the Metastatic Human Cancer infects his father, prompting him to return to Loop to counteract the Ring Virus, the cancer's real form.
- Bat Deduction: Realises the tape must be copied to escape the curse.
- Celibate Eccentric Genius: To an extent. Ryuji has a relationship of sorts with his assistant/student Mai, and claims to have raped three women, though he has no proof of it other than stories.
- Clone Degeneration: By choosing to activate the virus that speeds up the aging process of the clones, Kaoru (as a clone of Ryuji) ends up prematurely aging alongside the Sadako clones.
- Clone Jesus: Kaoru is a reincarnated Ryuji Takayama. As a baby, he was extracted form the Loop program and raised in the real world, but brought the Ring Virus with him, where it mutated into the Metastatic Human Virus cancer.
- Cool Teacher: Mai is affectionate towards him because of his kindness and encouragement.
- Cloud Cuckoolander: He is pretty nuts.
- The Hero Dies: In Happy Birthday.
- Heroic Sacrifice: Kaoru willingly dies to stop the Metastatic Human Virus in the real world and is reborn in the Loop world as the revived Ryuji.
- I Have Many Names: His real name is Ryuji Takayama, but after he is transferred to the real world, he is renamed Kaoru Futami by his adoptive parents. After returning to LOOP, he dons the identity of Seiji Kashiwada.
- The Medic: Works as a medical student.
- Mentor Occupational Hazard: Meets his end in Ring to eliminate Kazuyuki's source of information, though he gets better.
- No Dead Body Poops: Averted with his staged video of being hanged in S. Takanori notes that as "Seiji" is hanging himself, a dark stain develops in the area around his pelvis.
- The Philosopher: Prone to philosophising about life, along with his own apparent crimes as a rapist.
- Punch-Clock Hero: Claims to have raped several girls.
- Rapid Aging: After returning to LOOP and activating the virus that speeds up the aging of clones, Kaoru, by virtue of being a clone, rapidly ages in a matter of months and dies before his girlfriend Reiko gives birth to their son.
- Reincarnation: Kaoru was cloned from Ryuji's genes in LOOP. He is genetically identical to Ryuji, but has no memories of his past life whatsoever.
- Romancing the Widow: Kaoru starts a relationship with Reiko and has a son with her, though this ends up leading Reiko's first son, Ryoji, to commit suicide.
- Sacrificial Lion: Killed by the virus to prove it hasn't been stopped.
- Straw Nihilist: Makes quips about wanting the world to end. Ends up playing a part in its "evolution" by helping spread Sadako's virus. It's later revealed, however, that he does this mainly to fool Sadako, as he actually wants to save the world from her domination.
- Teeny Weenie: When Ando does an autopsy on Ryuji's body, he notes to his amusement Ryuji's unimpressive sexual attributes.
- Tomato in the Mirror: In Loop, Kaoru finds out that he is the clone of Ryuji Takayama, an artificial life form in a virtual reality world.
- Unreliable Narrator: Mai's insight regarding his relationships and his autopsy revealing he had a very small penis cast doubt on whether he'd ever actually raped anyone or if he made it all up.
Sadako Yamamura
Sadako Yamamura
The central character of the series. Sadako was a teenage girl with Psychic Powers, had a pretty miserable childhood, and was then chucked down a well to her death. Years on, her spirit haunts a videotape which contains a curse that will kill whoever watches it within seven days unless they copy it and show it to someone else.- Achilles' Heel: Sadako's tape is initially both her strength and weakness. The ring virus can only spread if someone copies the tape and shows it to someone else, though the deaths of those who do watch it may inspire others to investigate the tape - and that actually happens. When all of the tapes are destroyed, however, Sadako finds another way to spread the curse: books.
- Alas, Poor Villain: Usually invoked once per installment, when her backstory is taken into account.
- Back from the Dead: Sadako's entire plan was to be reborn, since she had a premonition of her return before she died and made the cursed videotape and subsequent Ring Virus to achieve her goal. She succeeds and proceeds to spread her curse through Asakawa's journal as a published novel, and then through a film adaptation.
- Big Bad: Of the whole series.
- Biomanipulation: Sadako created the Ring Virus this way, mutating a smallpox strand her rapist gave her, to the point she reworked it to cause heart failure, and impregnate women with her own DNA to come back from the dead.
- Blessed with Suck: Her powers brought Sadako and her loved ones a lot of grief.
- Brown Note: The videotape in all of its forms.
- The Chessmaster:
- Her primary goal is to inflict suffering on the world. However, she will forgo this for the sake of a more immediate goal.
- In Spiral, she actually grants Ando a reprieve from death in return for his assistance and non-interference in her resurrection plan.
- Fetus Terrible: In Coffin the Sky, Mai unwillingly gives birth to a reborn Sadako who grows at a phenomenal rate and can escape a roof ventilation shaft like an adult.
- Haunted Technology:
- Her cursed videotape.
- A recorded piece of audio acts as a precursor to the videotape in Lemon Heart. Like the tape, it inflicts the ring virus on its listeners, but has a much slower rate of infection (victims only die some thirty years after they heard the audio).
- Hermaphrodite: Sadako was born with androgen sensitivity syndrome, meaning she had both a penis and a vagina, but was infertile, and otherwise identified as a female. When Jotaro Nagao discovered this, he promptly threw her down a well. She's later reborn as a "complete hermaphrodite", meaning she can give birth without a sperm donor.
- Intersex Tribulations: Sadako has Androgen Insensitivity Syndrome, an intersex condition that means she cannot give birth because she has XY chromosomes. This revelation tragically leads her plunge down the well. In Spiral, the reborn Sadako gains the ability to give birth, making her, as she puts it, "A complete hermaphrodite."
- No Celebrities Were Harmed: Sadako is based on one Sadako Takahashi, a Japanese woman said to have developed psychic powers and was a test subject for Dr. Tomokichi Fukurai, who Dr. Ikuma is based on.
- Parental Abandonment: Sadako's mother Shizuko committed suicide from depression.
- Psychic Powers: Sadako pretty much has displayed the entire variety of powers listed on the trope's page. Her most notably power is psychography (or "nensha") which she used to create the videotape. She is able to alter the genetics of human biology and mutate a smallpox strand with her DNA into a virus able to cause tumors, heart attacks, and impregnate women with said DNA to ensure that she can be resurrected, as well as create clones of the dead.
- Rape as Backstory: Sadako was sexually assaulted by Dr. Nagao, who discovered she was a hermaphrodite and chucked her down the well.
- Sealed Evil in a Can: Thrown down a well to die, leading to her rise as a vengeful ghost.
- Star-Crossed Lovers: Sadako and Toyama. Sadly Doomed by Canon.
- Start of Darkness: Thrown down a well leads to her becoming a vengeful ghost.
- Thrown Down a Well: After she was raped by Dr. Nagao, he threw her down a well, pelted her with rocks to make sure she died, before closing the lid.
- Trauma Conga Line: Where to begin? Her mother lost her second child to illness, became depressed and eventually committed suicide, Sadako joined an acting troupe and found love but a recording of Sadako and her boyfriend Toyama having sex killed six people, her father developed tuberculosis, and then she was raped by Jotaro Nagao who discovered she was a hermaphrodite and chucked her down a well to her death.
- The Virus: The Ring Virus, a mutated strand of smallpox which can lead to heart attacks or impregnation in female victims (but only if they have sex while infected). The cursed videotape is intended to spread like a virus, being copied and passed onto another person to escape death.
- Xanatos Gambit: Sadako's plan goes pretty much as she hoped, also backed up by the visions she had of the successful outcome.
Kenzo Yoshino
Kenzo Yoshino
A journalist friend of Kazuyuki. Working in the Yokosuka city hall press club, Yoshino performs secondary tasks for Kazuyuki to find information of Sadako's past.- Curiosity Is a Crapshoot: Very wary around urban legends but investigates Sadako's past on Kazuyuki's request, but is kept in the dark about some of the more darker elements of his friend's investigation. Ends up being one of the few characters to escape Sadako's wrath in one piece.
- A Day in the Limelight: Has his own chapters in Ring and is a supporting player in Lemon Heart.
- Fire-Forged Friends: With Kazuyuki. They were coworkers back when Kazuyuki still worked at the Yokosuka press club.
- Intrepid Reporter: Goes to great lengths to help Kazuyuki learn of Sadako's fate.
Shizuka and Yoko Asakawa
Shizuka and Yoko Asakawa
Kazuyuki's wife and one-year-old daughter. When Kazuyuki carelessly leaves the cursed videotape in their apartment, Shizuka and Yoko watch it, further pressuring Kazuyuki to find the solution to stop the curse. He fails to do this, however, and the mother and daughter are killed off by the curse. Shizuka's maiden name is Oda.- Healthcare Motivation: Kazuyuki finds the determination to find the cure for the virus when Shizuka and Yoko end up watching the tape.
- Housewife: Shizuka is the ordinary housewife of a typical Japanese salaryman.
- Killed Off for Real: In Spiral, the Asakawa car is found crashed with Kazuyuki catatonic and Shizuka and Yoko dead. Apparently, the latter two died before the crash happened, as they were claimed by the ring virus.
- Spell My Name With An S: Shizuka's name is romanized as "Shizu" in the English translations, but the correct pronunciation is "Shizuka."
- Wet Blanket Wife: Shizuka complains that Kazuyuki is too preoccupied by work to care much for her or Yoko.
Mai Takano
Mai Takano
Ryuji's student and possible girlfriend. Although she has a minor role in Ring, her role is expanded in Spiral, where she assists Mitsuo Ando investigate the ring virus, only to fall victim to it. She is forced to give birth to a Sadako clone, and dies in the process.- And I Must Scream: Used by Sadako as an incubator for her resurrection. She is trapped in the ventilation shaft on her apartment roof, unable to move as Sadako gives birth to herself and leaves Mai to die.
- Ascended Extra: Has a relatively minor role in Ring, but gets a major boost in Spiral.
- A Death in the Limelight: The gist of Coffin in the Sky.
- Face Full of Alien Wing-Wong: Sadako impregnates her with herself.
- Heroic BSoD: After finding Ryuji's corpse.
- Killed Off for Real: In Spiral.
- Mystical Pregnancy: She becomes pregnant despite being a virgin. The culprit is Sadako, who infects Mai when she is at her most fertile.
- Supernaturally Young Parent: Sadako grows up into an adult mere weeks after being born from Mai's womb. She is impregnated and gives birth to Akane Maruyama not too long after, making Mai a grandmother in her twenties.
- Teacher/Student Romance: Possibly with Ryuji, although Mai denies that they ever had sex.
Jotaro Nagao
Jotaro Nagao
The last smallpox patient in Japan, and the person responsible for the death of Sadako Yamamura. In the present day, he works as a doctor in Atami, Shizuoka Prefecture, and is eventually confronted by Kazuyuki and Ryuji during their investigation into the ring virus.- Karma Houdini Warranty: After raping and killing Sadako, Nagao was cured of smallpox and went on to open a clinic and start a family. But after Kazuyuki and Ryuji confront him for his role in Sadako's death, he has a mental breakdown. In Spiral, Ando tries contacting Nagao for clues regarding the virus, only to find out that the clinic is closed because Nagao has been driven insane.
- Small Role, Big Impact: Despite playing a small role in the series, he was the one who infected Sadako with the smallpox virus and killed her, a catalyst to the birth of the ring virus.
- Unsettling Gender-Reveal: While raping Sadako, Nagao saw her underside and realized that she had a penis. He then threw her down a well.
- Unwitting Instigator of Doom: Obviously, he has no idea that his smallpox virus would contribute to The End of the World as We Know It.
- What Happened to the Mouse?: Nagao is last mentioned in Spiral, where Ando is informed that Nagao has been "sick" ever since Kazuyuki and Ryuji visited him the previous novel.
Tomoko Oishi
Tomoko Oishi
Kazuyuki's teenage niece, the daughter of his wife, Shizuka's sister Yoshimi Oishi. The first victim of the series, she is killed by the ring virus a week after watching Sadako's cursed videotape, driving Kazuyuki to start investigating.- Intro-Only Point of View: The very first chapter of Ring is narrated from her perspective, but she dies at the end of it.
- Killed Off for Real: In the prologue of Ring.
- Plot-Triggering Death: Her death, as well as three other people who watched the tape, leads Kazuyuki to begin researching about the ring virus.
- Spanner in the Works: It's thanks to Tomoko and her friends' playful deletion of the video that explained the solution to stop the curse that the ring virus evolved from infecting videotapes to books, which claims much more victims but also alerts the situation to the people outside LOOP, leading to its eventual demise. In fact, we don't even know what the original solution to stop the virus was; the "copying the tape and showing it to someone else" is only a speculation from Kazuyuki's part, as it fails to save his wife and daughter anyway.
Shizuko Yamamura
Shizuko Yamamura
Sadako's mother, a psychic who could burn images onto paper. She had an affair with Doctor Heihachiro Ikuma, who encouraged her to show off her powers to the press to gain fame. When they attacked her for being a fraud, however, she became depressed and eventually committed suicide by jumping into Mount Mihara.- Artifact of Power: Shizuko's psychic abilities manifested after she fetched the statuette of En no Ozunu from the ocean.
- Driven to Suicide: She became mentally ill thanks to repeated harassment from the press, before committing suicide.
- Missing Mom: Died when Sadako was a little girl.
- The Mistress: She started an affair with the already-married Heihachiro Ikuma.
- Outliving One's Offspring: Her second child, a boy, died shortly after birth.
- Posthumous Character: Died decades before the events of Ring and only seen in flashbacks.
- Psychic Powers: She could burn images onto paper.
- Sanity Slippage: After she was branded a fraud, culminating in her killing herself.
Heihachiro Ikuma
Heihachiro Ikuma
Sadako's father, a professor from Tokyo University who had an affair with Shizuko despite having a wife. His attempt to gain fame by showing off Shizuko's powers resulted in her being driven to suicide and Ikuma losing his prestige in the scientific community. In his madness, he attempted to unlock psychic powers of his own, but ended up infected by tuberculosis, requiring him to recuperate at a sanatorium.- Disastrous Demonstration: Arranged Shizuko's public demonstration of her powers. It didn't go very well, leading to her suicide.
- Expy: Dr. Ikuma is based on Dr. Fukurai, a real life Deadly Doctor, who tried to prove the existence of psychic powers. It took the deaths of two women for him to call it quits.
- Incurable Cough of Death: He suffered tuberculosis and was remanded in a sanatorium for the rest of his life.
- Meditating Under a Waterfall: Sat under waterfalls to try to gain psychic powers but it only gave him tuberculosis.
- Outliving One's Offspring: He outlived his daughter, Sadako, who was visiting him when she was raped and killed by Dr. Nagao.
- Posthumous Character: He succumbed to tuberculosis sometime after Sadako's death.
- The Professor: Was a professor in Tokyo University.
- Sanity Slippage: Like Shizuko, Ikuma descended into insanity after he was branded a fraud by the press, though he did not go as far as killing himself.
Introduced in Spiral
Mitsuo Ando
Mitsuo Ando
The protagonist of Spiral. Mitsuo Ando is a doctor who is grieving his son's death, traumatized by the accident and blaming himself for it and for his wife's emotional condition. Because of that, he has suicidal tendencies, though not brave enough to do the deed. He is also very intelligent and curious, and a very good person who wants to do the right thing, but is easily tempted by beautiful women.- Babies Ever After: S reveals that not only Ando got Takanori back, his marriage was saved, and he conceived another child with his wife, Takanori's unseen younger sister.
- Broken Pedestal: Upon learning that his friend Ryuji is cooperating with Sadako to bring about the end of the world, Ando is disgusted and thinks to himself that, after gaining Takanori back, he will have no more involvement with the two whatsoever.
- Classical Anti-Hero: Ando works as a pathologist, his son drowned, and hates himself for not minding Takanori properly.
- The Coroner: Performs the autopsy on Ryuji's corpse, kicking off Spiral's story.
- Deal with the Devil: Ando agrees to spread Sadako's virus in exchange for resurrecting Takanori.
- Driven to Suicide: Tried this but was too afraid to.
- Foot-Dragging Divorcee: His wife filed for divorce after Takanori's death, but Ando procrastinates signing the divorce papers because he thinks their marriage can still be saved.
- Guilt Complex: For Takanori's death.
- Obnoxious In-Laws: Averted. Akane thinks that Mitsuo will be condescending to her for being poor, but when Takanori and Mitsuo talk about her later, it's clear that Mitsuo has no problem with Akane becoming his future daughter-in-law.
- Outliving One's Offspring: He outlived his son, Takanori, who drowned while they were playing at a beach. He still blames himself for it, especially since his wife sought divorce afterwards. In the ending of Spiral, he makes a deal with Sadako to resurrect Takanori in exchange for staying put regarding her plans to clone herself in mass.
Miyashita
Miyashita
Miyashita is Mitsuo Ando's co-worker at the pathology department and also his friend. He is a smart person, down to Earth, scientifically oriented and disbelieves in the paranormal.- Agent Scully: Disbelieves in the curse and the paranormal until he is dragged into it himself.
- The Coroner: Works as a coroner alongside Ando.
- Heterosexual Life-Partners: With Ando.
- The Medic: Rieko is a microbiologist but knows how to treat people too.
- Necessarily Evil: Aids Ando is spreading the Ring Virus in order to save his friend and himself after handling Asakawa's cursed journal.
Takanori Ando
Takanori Ando
Mitsuo Ando's toddler son, who died years ago in a freak swimming accident. At the end of Spiral, Ando agrees to stop hindering Sadako in exchange for resurrecting Takanori. Takanori is the protagonist of S, set 25 years later, in which he is dragged into the ring virus case when his pregnant girlfriend, Akane, is haunted by a serial killer.- Artificial Human: The Takanori who appears at the end of Spiral and subsequently becomes the protagonist of S is a clone of the original Takanori, who died in a swimming accident and whose body is still presumably somewhere in the Pacific Ocean. Upon her own rebirth, Sadako was imbued with the power to recreate anyone, even deceased people, as long as she has their genes. Fortunately, Mitsuo Ando managed to grab some hair from the original Takanori when he tried to save him.
- Back from the Dead: Takanori died when he was three years old, but his father made a deal with Sadako to resurrect him two years later. Mitsuo refuses to disclose the details, so Takanori can only guess the truth, and remains in the dark even twenty five years later.
- "Eureka!" Moment: When he realizes that Seiji Kashiwada and Ryuji Takayama are the same person, and he has met him when he was a toddler.
- One Thing Led to Another: How he describes him impregnating Akane. They were simply spending a holiday at a resort, but then one thing led to another and suddenly Akane is pregnant.
- Posthumous Character: Is this for much of Spiral, but obviously no longer the case once he is resurrected.
- Surprise Incest: He and Akane were born from the same womb, though neither is squicked out by this.
- Tomato in the Mirror: Takanori deduces that he was dead but got resurrected, judging by how the family registry lists him as "deceased" for two years.
- Understanding Boyfriend: He comforts Akane when she accidentally sees the video of Seiji Kashiwada's execution, and promises to keep track of her when she admits that she is being stalked by someone.
- Uptown Girl: Inverted with him being the uptown boy to Akane. Takanori is the upper-middle-class son of a doctor while Akane is an orphan who leads a modest life as a high school teacher.
Introduced in Loop
Reiko Sugiura
Reiko Sugiura
A widowed mother and a carrier of the Metastatic Human Cancer Virus, which she passed to her son, Ryoji. She has an affair with Kaoru Futami, who tutors Ryoji, but this causes the latter to commit suicide upon knowing the truth. When she admits to being pregnant afterwards, Kaoru becomes determined to find a cure in the hopes that their soon-to-be-born son will grow up in a world without the virus.- Age-Gap Romance: With Kaoru, who is fifteen years her junior.
- A Day in the Limelight: She is the POV character of Happy Birthday.
- Driven to Suicide: After Ryoji's suicide, she nearly considers suicide herself because she doesn't want her son to grow up in a world with the ring virus.
- Healthcare Motivation: Kaoru begins searching for a cure to the ring virus so his and Reiko's son can grow up healthy.
- My Girl Back Home: The ending of S implies that Ryuji is attempting to return back to the real world so he can reunite with Reiko and their son.
- Outliving One's Offspring: Outlives Ryoji, who kills himself upon learning that his mom is banging his teacher.
- Someone to Remember Him By: Her son with Kaoru, who is born several months after Kaoru dies in LOOP.
Ryoji Sugiura
Ryoji Sugiura
Reiko's son with her deceased husband who is infected by the Metastatic Human Cancer Virus.- Delicate and Sickly: He grew up suffering with the Metastatic Human Cancer.
- Driven to Suicide: After discovering Reiko's and Kaoru's affair, he jumps off a building to his death.
- Goodbye, Cruel World!: He leaves behind a suicide note, which basically states that he does not want to get in the way of Reiko's relationship with Kaoru.
- Parent with New Paramour: Ryoji eventually learns that Reiko is sleeping with Kaoru Futami, his teacher. He does not take this well, and resorts to committing suicide.
Toru Amano
Toru Amano
A doctor who worked in the LOOP project and a friend of Hideyuki Futami, Kaoru's father.- Mr. Exposition: Explains to Kaoru about LOOP, its history, the ring virus, its connection with the Metastatic Human Cancer Virus, and the attempts to find a cure for it.
Hideyuki and Machiko Futami
Hideyuki and Machiko Futami
Kaoru Futami's adoptive parents. Hideyuki is a mathematician involved with the LOOP project who was infected by the Metastatic Human Cancer Virus, while Machiko is a graduate of American studies.- The Cuckoolander Was Right: Kaoru initially doesn't take Machiko's suggestion about the Native American Ancient One seriously. He later learns that while the mythical figure does not exist, there is a secret research laboratory in the United States that was built to search for a cure for the MHC.
- Despair Event Horizon: After Hideyuki's diagnosis, Machiko slowly slipped into depression as she turned to alternative medicine to cure her husband.
- Mother Nature, Father Science: Hideyuki majored in hard science while Machiko majored in soft science.
- Outliving One's Offspring: Outlive Kaoru, who dies finding the cure for the MHC.
Professor Eliot
Professor Eliot
An American doctor involved in the LOOP project who has been researching for a cure for the ring virus ever since it escaped to the real world.- The Hermit: Lives in an isolated laboratory in the American Rockies.
- Well-Intentioned Extremist: He was the one who alerted Mitsuo Ando to begin investigating the ring virus, which would lead to Mai's death and the spread of the ring virus plague to the whole world. However, he did this so the cure for the MHCV, which developed out of a rogue strain of the ring virus, can be found.
Introduced in Birthday
Hiroshi Toyama
Hiroshi Toyama
Sadako's ex-boyfriend and associate at Theater Group Soaring. Toyama is a middle-aged man with a wife and children, but still has hopes to see Sadako again, since their relationship abruptly ended when she disappeared from the faces of the earth.- Killed Off for Real: In Lemon Heart.
- Peaceful in Death: He is happy in death, since he finally reunites with his beloved Sadako.
- The One That Got Away: Sadako is this to him, since he never stopped loving her, even years after their relationship ended.
- Star-Crossed Lovers: Sadako was forced to flee Toyama when she was suspected of murder, then died shortly after, something that Toyama only figures out more than two decades later.
- Understanding Boyfriend: He was more than willing to accept Sadako's peculiarities, but this did not stop her from having to disappear when she was suspected of Shigemori's death.
Introduced in S
Akane Maruyama
Takanori Ando's pregnant girlfriend. She is an orphan who works as a high school teacher. It is later revealed that she is the daughter of Ryuji Takayama and Masako, the Sadako clone born to Mai Takano.
- Best Served Cold: It's implied that she pushes Hiroyuki to his death in the train station, as revenge for trying to kill her and gaslighting her.
- Imperiled in Pregnancy: She is stalked by a serial killer, Hiroyuki Niimura, who once hunted Sadako clones a decade ago.
- Surprise Incest: She and Takanori were born from the same womb, though neither is squicked out by this.
- Tomato in the Mirror: Learns that her mother, Masako, was a Sadako clone. And her father is Ryuji Takayama, who had a heavy involvement in the ring virus himself.
- Uptown Girl: Inverted with her being the poor girl to Takanori's rich boy.
Hiroyuki Niimura
Hiroyuki Niimura
A former student of Ryuji Takayama. Ten years ago, he went into a crusade to kill off all Sadako clones in the world, despite Ryuji's belief that they deserved the chance to exist.- Big Bad: Of S, though he is offscreen for much of the book.
- Karma Houdini Warranty: He escapes justice for ten years, but eventually dies in a suicide that Takanori thinks may been instigated by his former victim, Akane Maruyama.
- Knight Templar: He killed the remaining Sadako clones even though they were harmless (the ring virus having been eradicated by Ryuji's research) and, most importantly, still children.
- Never Suicide: Takanori speculates that Akane may have killed Hiroyuki in the train station, but stages it to look like a suicide.
- Serial Killer: He was the true serial killer of the four girls ten years ago, not Seiji Kashiwada.
- Would Hurt a Child: And kill them too.
Seiji Kashiwada
Seiji Kashiwada
A man accused of the murder of four girls ten years before the events of S, who is executed in the prologue of the novel.- Acquitted Too Late: Takanori and Akane learn that Seiji was innocent of the murders... a year after he was executed by hanging.
- Intro-Only Point of View: Narrates the prologue of S, which ends with his execution.
- No Dead Body Poops: Averted, as he describes himself urinating while he is choked to death.
