Kurihara is the Author’s mentor figure, an architectural draftsman whose intellect and deductive reasoning are essential to solving the novel’s central puzzle. Akin to Arthur Conan Doyle’s famous detective, Sherlock Holmes, Kurihara is a static, round character, defined by his sharp, analytical mind and his ability to perceive the hidden narratives within architectural designs. While the Author collects the stories, it’s Kurihara who provides the key insights that connect them, explaining how unrelated floor plans, family histories, and tragedies all lead back to the Rebirth Congregation. His apartment is a sanctuary of intellect, a place where the chaotic fragments of the story are brought into order. His function is primarily expository, yet his deductions are so central to the plot’s resolution that he becomes the intellectual engine of the narrative, revealing the grand, sinister design that links all 11 buildings.

Yaeko is the tragic central figure of the novel; she’s a round and largely static character whose life was a fabric of exploitation and suffering. Her existence is the axis around which the entire multi-generational mystery revolves. From her traumatic birth, the loss of her arm, and the death of her mother to her eventual death, Yaeko was consistently victimized by the actions of others. Her body was first commodified in the okito, where she was forced to act as part of the human surveillance system that kept the other mothers and children in line, and later deified by the Rebirth Congregation, where the limbs she lost were rebranded as symbols of holy sacrifice. This transformation from a survivor of violence into a religious icon is framed as a sophisticated form of imprisonment, forcing her to publicly display the physical markers of her trauma to manipulate others into funding her captors’ wealth. Her daughter’s plot to create the cult as an act of revenge ensured that Yaeko could never escape her past, making her a living monument to the very suffering she endured.

Yaeko’s character demonstrates a deep internal conflict between her deep-seated shame and her capacity for love. She meticulously hid her prosthetic limbs with long skirts and gloves, suggesting a sense of shame about her body. This made her role as the Holy Mother, where she was displayed “barely covered,” a particularly cruel form of psychological torture. Despite this, she showed genuine kindness and protective instincts, particularly toward children like Mitsuru Nishiharu and her own granddaughter Mitsuko. Her final act, falling down the stairs to spare Mitsuko from having to carry out their family’s murder plot, was the ultimate expression of this protective love (although it’s left ambiguous whether Yaeko really did this or whether Mitsuko dreamed this to revise her complicity in her grandmother’s death). It was a desperate, tragic choice that emphasizes her role as a perpetual sacrifice, a woman whose life was defined by what was taken from her and what she gave up for others. Her story is the ultimate embodiment of The Compounding Effect of Secrecy on Trauma, as the initial secret of her birth cascaded into a lifetime of tragedy.

Masahiko is a major antagonist, a flat and static character whose actions have been driven by greed, lust, and an obsession with public image. As a chairman and the former president of Hikura Homes, he represents corporate corruption and the moral decay hidden beneath a veneer of success. His defining trait is his exploitative nature; he preys on the vulnerable for personal and financial gain. This is first established through his patronage of the okito, where he used his wealth to force Yaeko’s daughter into abusive sex work before erasing Yaeko’s debt to make them feel indebted to him. While helping Yaeko’s daughter found the Rebirth Congregation, he co-opted Yaeko’s life story and physical trauma, transforming her into the “Holy Mother” to create a lucrative business model that preyed on the guilt of its members. Rather than a true believer, he’s a cynical opportunist who understands how to weaponize faith and architecture to control people.

His influence permeates the novel, from the poorly designed houses that have sown discord among families to the purpose-built structures of control like the Hall of Rebirth. The rumors about him abusing a young girl, which hint at his relationship with Yaeko’s daughter, reveal his hypocrisy and the deep-seated corruption that he projected onto others through his sermons on sin. His speech to the cult members, where he warned of children inheriting their parents’ sin, was a masterful act of psychological manipulation, deflecting from his own transgressions while solidifying his control over vulnerable people. Masahiko is a predator who has used his power, wealth, and position to build an empire founded on the suffering of others, making him the architect of much of the novel’s central tragedy.

Although she remains mostly off-page and unnamed, Yaeko’s daughter is another major antagonist whose motivations are central to the novel’s climax. Her character is a chilling demonstration of how trauma can curdle into a desire for revenge. Having been forced into sex work as a child at the okito, she developed a deep-seated resentment toward her mother, Yaeko, whom she blamed for her suffering. This unresolved anger became the driving force behind the creation of the Rebirth Congregation. She manipulated her husband, Masahiko Hikura, using his history of pedophilia as leverage to force him to establish the cult. This reveals her to be a cold, calculating strategist who’s far more powerful than the men she ostensibly serves.

The cult was her masterwork of psychological torture, a grand, theatrical performance of revenge designed for an audience of one: her mother. By elevating Yaeko to the status of a goddess and building houses in the shape of her mutilated body, she forced her mother to endlessly relive and display her trauma on a massive scale. This act transformed Yaeko’s private shame into a public spectacle, a cruel and humiliating punishment that emphasizes the theme of The Compounding Effect of Secrecy on Trauma. Her character demonstrates the destructive cycle of abuse where a victim becomes a perpetrator, as she inflicted a new form of suffering on the person she held responsible for her own.

Akinaga is Mitsuko’s brother and a secondary antagonist who represents the cold, pragmatic continuation of the Hikura family’s corrupt legacy. As the current president of Hikura Homes, his primary motivation is the preservation of the family business and its public image, a goal for which he’s willing to commit murder. His character is defined by a chilling lack of empathy, particularly in his treatment of his grandmother Yaeko. He viewed her less as a family member than as a liability, a living reminder of the family’s connection to a disbanded cult that could tarnish their reputation. His solution was to imprison her in a windowless room, effectively erasing her from the world.

The narrative initially frames Akinaga as Mitsuko’s father, suggesting that Yaeko was married to Akinaga’s father, Masahiko, and that Mitsuko was the young child who was imprisoned in the okito with Yaeko. Toward the end of the novel, Akinaga is deduced to be Mitsuko’s brother, making Yaeko’s daughter their mother. This changes the Author’s initial suspicion that Akinaga designed and executed the murder plot against Yaeko. In point of fact, the revelation that Akinaga and Masahiko have both submitted themselves to Yaeko’s daughter’s rule underscores her menace and the cunning with which she has taken over their family. Akinaga is a flat, static character who embodies the final, destructive stage of the generational harm that plagues the Hikura family, prioritizing corporate stability over human life.

Mitsuko is a dynamic and round character whose journey from a manipulated child to a woman seeking atonement provides one of the novel’s most personal and tragic arcs. As a child, she was an outcast in her own family, valued only for her use as a propaganda tool for the Hikura Homes brand. Her only genuine connection was with her grandmother Yaeko, which made her father’s demand that she participate in Yaeko’s murder all the more destructive. Mitsuko’s internal conflict is central to her character; she was torn between the instinct for self-preservation and her love for her grandmother. This conflict was so deep that her mind created a false memory, a dream in which she defied her parents and saved Yaeko, as a psychological defense against the unbearable guilt of her complicity.

The discovery that she may have been responsible for her grandmother’s death shattered this defense and set her on a path of self-imposed punishment. By cutting ties with her wealthy family and choosing the difficult, low-paying work of a caregiver, Mitsuko has attempted to atone for her past. Her confession to the Author is an act of self-flagellation and absolution; she insists on her own culpability, rejecting any narrative that casts her as a survivor. Her story highlights the deep psychological harm inflicted by the Hikura family’s secrets and the lifelong burden of guilt carried by its youngest member.

Mr. Kasahara is a dynamic character who undergoes a significant transformation from a selfish philanderer to a man consumed by guilt and a desperate need for atonement. Initially portrayed as a neglectful father and husband, his defining characteristic is his irresponsibility. His affair with his neighbor, Mrs. Matsue, was driven by hedonism, but it inadvertently triggered a destructive tragedy that forced him to confront the consequences of his actions. The fire and the death of his mistress and their unborn child served as the catalyst for his change, plunging him into a state of melancholy and guilt.

His journey into the world of the Rebirth Congregation was a direct result of this guilt. He became a fervent believer, embracing the cult’s doctrine as a way to alleviate his sin and, most importantly, to protect his other child, Naruki. The theme of Guilt as a Tool of Emotional Manipulation is perfectly illustrated by his actions; he remodeled his house and brought Naruki to perform the “sacrament,” desperately trying to prevent a repeat of the tragedy with Mrs. Matsue. When Naruki was taken from him and died, his faith shattered, and his grief turned into rage against the Holy Mother. He died by suicide in an attempt to seal the “heart” of his house, a tragic, ritualistic expression of his despair and resentment, showing that even in his final moments, he was still captive to the cult’s twisted ideology.

Hayasaka serves as an unreliable narrator whose account of Yaeko’s death is filtered through the lens of her own childhood insecurities and class resentment. As a “company man’s daughter” in a school for the wealthy (86), she felt inferior, and this feeling colors her perception of Mitsuko and the events at the “mousetrap house.” Her theory that Akinaga designed the house to kill his mother is astute and partially correct, but she misinterprets key details because she’s an outsider to the family’s deeper secrets. Her focus on status, exemplified by her own rise to become a wealthy CEO, reveals her lasting preoccupation with the social hierarchy that defined her school years. Ultimately, her story is important for providing a detailed look inside the Hikura household, but her personal biases prevent her from seeing the full picture.

Hiroki is a key supporting character whose life is defined by the trauma of the fire that killed his parents. His belief that his devoutly religious father murdered his mother is a compelling but incorrect theory born from an attempt to make sense of an incomprehensible tragedy. The footsteps he heard and his father’s strange behavior are essential clues to the events of that night, but his interpretation is flawed, leading him to a lifetime of quiet resentment. He presents a stoic and successful facade as an adult, but his tight-fisted anger and his continued friendship with Chie Kasahara reveal a man still grappling with the unresolved events of his past. His story, when juxtaposed with Chie’s, demonstrates how multiple, conflicting narratives can emerge from the same event, each shaped by the individual’s unique perspective and trauma.