Inside the ‘Rat Man’s’ Room: The Crippling Isolation and Bizarre Mythology of Japan’s Most Withdrawn Serial Killer

In the late summer of 1988, a shadow fell across the suburbs of Tokyo and nearby Saitama Prefecture that would haunt Japan for decades to come. Over the course of merely thirteen months, four young girls vanished from the streets and playgrounds where children should have felt safe. Their abductor and killer was Tsutomu Miyazaki, a man whose crimes would become etched into the collective consciousness of an entire nation as one of the most horrifying examples of serial murder ever documented in modern history. But the story of how a young man from a prominent, wealthy family descended into unimaginable darkness reveals far more than just the details of violent crimes, it exposes the psychological fragmentation that can occur when physical difference meets social rejection, when access to disturbing fantasy collides with an unstable mind, and when a family’s silence becomes complicit in tragedy.

Tsutomu Miyazaki entered the world on August 21, 1962, in Itsukaichi, Tokyo, born into circumstances that by all conventional measures should have promised comfort and opportunity. His family operated a regional newspaper company of considerable prominence in their community, and their lineage carried weight and prestige, his grandfather and great-grandfather had both served on the town council, establishing the Miyazaki name as one synonymous with influence and standing. From a material perspective, the young Tsutomu lacked for nothing. His family was wealthy, and the trappings of success surrounded him from birth. Yet this outward prosperity masked a profoundly troubled domestic reality that would prove far more consequential than any amount of financial security could compensate for.​

The cruelty nature sometimes inflicts on the human body presented itself from the moment Tsutomu’s life began. He was born prematurely, and more significantly, he was afflicted with a rare congenital condition called radioulnar synostosis, a birth defect that fused the joints of his hands and wrists, leaving him unable to bend his wrists upward. His hands, permanently locked in an unnatural position, became the physical manifestation of everything that would make him different, marked, and fundamentally separated from the world around him. This deformity, which should have evoked compassion and adaptive support from his family, instead became the catalyst for what child development experts might recognize as early attachment trauma and social isolation.​

Due to his parents’ preoccupation with their business responsibilities, young Tsutomu was relegated to the care of his grandfather and an intellectually disabled man whom the family employed as a nanny. This was not a deliberate choice born of cruelty, but rather the product of a family prioritizing professional achievement over emotional presence. What Miyazaki would later reveal in his confession, that he desperately wanted his parents “to listen to him about his problems” but believed they were too consumed with material concerns to notice his suffering, speaks volumes about the emotional vacuum at the center of his childhood home. His parents were physically present but emotionally absent, and in that absence grew a void that would never be adequately filled.​

When Tsutomu entered elementary school, the other children responded to his deformity with the casual cruelty that children are capable of when confronted with physical difference. He was ostracized, bullied, and isolated, which drove him further inward. He became a solitary figure, developing a rich fantasy life that would become increasingly his primary retreat from a world that seemed determined to reject him. Despite this social torment, Miyazaki demonstrated considerable academic ability. He attended Meidai Nakano High School in Nakano, a prestigious institution associated with Meiji University, and initially ranked among the top students in his class. The contradiction between his intellectual capability and his social alienation created a fundamental split within his personality, he was intellectually above his peers but socially exiled from them, a dynamic that would only intensify as he aged.​

However, the trajectory that had initially shown promise would soon reverse dramatically. By the end of his high school years, Miyazaki’s academic performance had deteriorated sharply, and his final class ranking had plummeted to 40th out of 56 students. The psychological weight of prolonged isolation, combined with the knowledge that he would not receive the customary university admission offered to top Meidai Nakano students, struck a devastating blow to his already fragile sense of self-worth. Instead of pursuing the path toward becoming an English teacher as he had once planned, Miyazaki attended a local junior college where he studied photography technology. His life was increasingly becoming a series of diminished opportunities, each small disappointment reinforcing the narrative of rejection and inadequacy that had been building within him since childhood.​

By the mid-1980s, Miyazaki had moved back into his parents’ home, sharing a room with his elder sister in the house where he had endured so much emotional neglect. His family expected him to eventually take over the family newspaper business, yet he felt no connection to this path, no desire to follow in his family’s footsteps. In the confined space of his bedroom, increasingly isolated and detached from the world around him, Miyazaki began to construct an elaborate fantasy universe through videotapes. He accumulated an extraordinary collection, eventually numbering 6,000, of material that included pornography, horror films, and violent anime. These were not casual viewing habits but an obsessive immersion in increasingly extreme imagery that seemed to provide him with a form of emotional regulation, a way to externalize his inner turbulence through the consumption of others’ depictions of violence and sexual transgression.​

The pivotal moment that seemed to accelerate his psychological deterioration came in May 1988, when his grandfather, the one family member he felt truly close to, the one person he believed had offered him genuine support, died. The loss was catastrophic. In an attempt to maintain some spiritual connection to his grandfather, Miyazaki engaged in an act that horrified his family: he consumed part of his grandfather’s ashes, believing this grotesque communion would somehow allow him to retain his grandfather’s essence. When his mother later discovered him watching his sister shower through a crack in the bathroom door, her response was not therapeutic intervention but a demand that he spend less time with his videotapes and more time working. When he physically attacked her in response to her criticism, the family’s dysfunction reached a breaking point, yet still no one sought professional mental health intervention for a man whose psychological deterioration was becoming increasingly obvious to those around him.​

In August 1988, less than three months after his grandfather’s death and with his psychological state continuing its downward spiral, Tsutomu Miyazaki crossed a threshold from which there was no return. On August 22, 1988, he spotted a four-year-old girl named Mari Konno playing near a park in the Tokyo area. He approached her with his camera in hand, the equipment of his profession, and lured her with the promise of taking beautiful photographs. He drove the child to an isolated location, where he subjected her to sexual abuse, photographed her, and then killed her by strangulation. The specific mechanics of her murder involved placing his deformed hands around a child’s neck and squeezing until she lost consciousness and died. He stripped her corpse, arranged her body in degrading positions, photographed her lifeless form, and left her body behind while taking her clothing with him, which he photographed obsessively for his collection.​

Mari Konno was simply gone. No one yet knew what had happened to her. There was no immediate sense of crisis, no visible monster apprehended. He had successfully evaded detection. For someone in Miyazaki’s psychological state, this success, this ability to commit an act of ultimate violence and escape consequences, would have reinforced rather than inhibited his darkest impulses. The years of rejection, humiliation, and rage that had accumulated within him had finally found an outlet.

Two months later, in October 1988, Miyazaki selected his second victim: Masami Yoshizawa, a seven-year-old girl who happened to be walking alone near where he was driving his black sedan. Again, he employed his photography as a pretext. He convinced the child to enter his car, drove her to an isolated area not far from where Mari Konno’s remains still lay undiscovered, murdered her through strangulation, subjected her corpse to sexual abuse and mutilation, and removed her clothing. The sheer repetition of these actions, the ritualistic nature of his crimes, suggests a compulsive cycle that had taken hold of him completely. He was no longer simply committing individual acts of violence; he was enacting a disturbing ritual that, within his fractured psychology, had acquired profound meaning.​

On December 12, 1988, Miyazaki’s murderous impulses drove him to select his third victim: another four-year-old girl named Erika Namba. The pattern remained consistent, the camera, the deception, the car, the isolated location, the strangulation, the sexual assault of the corpse, the removal of clothing. But this victim nearly exposed him. Through a series of circumstances, someone nearly caught him in the act, which caused him to accelerate his timeline and increase his recklessness. He was drawing closer to capture with each crime, yet his psychological compulsion seemed to override any instinct for self-preservation.​

The particularly chilling dimension of Miyazaki’s crimes involved what occurred after the moment of murder. For the first victim, Ayako Nomoto, a five-year-old whom he murdered on June 6, 1989, Miyazaki’s depravity reached its most graphic extreme. After driving her to his apartment in his black Nissan sedan and murdering her through strangulation, he stripped her corpse and arranged it in sexually explicit positions, then photographed the dead child’s body. The level of premeditation and planning involved in these acts suggests that Miyazaki had thought extensively about what he would do before ever leaving his home that day, that he had rehearsed these scenarios mentally through his videotape obsessions and was now merely translating his fantasy life into horrific reality.​

Within two days, as Ayako Nomoto’s decomposing corpse began to emit an unbearable odor in his small apartment, Miyazaki took a saw to her body and began systematically dismembering her. He removed her hands and feet specifically to prevent identification, deliberately ate portions of her flesh, and scattered the remains across multiple locations, her torso abandoned near a public toilet in a cemetery, her skull tossed down a ravine. Later, he would also drink the blood from one victim’s severed hands and consume pieces of their flesh, acts that elevated his crimes beyond serial murder into the realm of vampirism and cannibalism. The police, discovering Ayako’s torso, launched an intensive manhunt for the killer, and Miyazaki became increasingly frantic. He even returned to collect some of the scattered remains, hiding them in his room before eventually burning the remains to eliminate evidence.​

But Miyazaki’s pathological compulsion to photograph children and his complete inability to maintain any form of impulse control made his capture inevitable. On July 23, 1989, police officers spotted Miyazaki in Hachiōji, a Tokyo suburb, where he was attempting to take nude photographs of a young girl. In an act of unimaginable depravity, he was literally in the process of trying to insert a camera lens into the child’s vagina when the girl’s father appeared on the scene. This ordinary man, with no special training, did what law enforcement had been unable to do, he physically confronted Miyazaki, threw him to the ground, and apprehended him. Miyazaki attempted to flee but abandoned his vehicle in the process. When he later returned to retrieve his car, police officers were waiting to arrest him on charges of forcing a minor to commit indecent acts.​

What the police discovered when they searched Miyazaki’s small apartment and his car would shock even hardened investigators. Inside his residence, they cataloged approximately 5,763 videotapes, the majority containing pornographic material, violent anime, horror films, and disturbing content depicting child sexual abuse. Among his possessions were photographs of his victims, their clothing, and documentation of his crimes spanning back months. The physical evidence of his crimes was enormous, comprehensive, and damning. It was a complete archive of depravity.​

As news of Miyazaki’s arrest spread through Japan, the public was confronted with a horrifying realization: a man with profound mental illness and access to massive quantities of extreme sexual and violent imagery had murdered four young children over the span of less than a year. The case triggered a national moral panic, particularly focused on the “otaku” culture, the subculture of fanatic hobbyists and anime enthusiasts. The epithet “Otaku Murderer” was born from this moment, intended to suggest that anime culture, pornography, and fantasy media had somehow caused Miyazaki’s violence. This oversimplification would prove to be a disservice to understanding the true psychological and social factors that had produced him, yet the label stuck and shaped public discourse around his case for decades.​

Miyazaki’s trial, which began in March 1990, would last nearly a decade and a half, sixteen years of legal proceedings before any final judgment was rendered. During this extraordinarily extended judicial process, Miyazaki demonstrated no remorse for his victims or their families. Instead, he offered a disturbing and cryptic explanation for his crimes: he claimed that a “Rat Man,” an imaginary creature that he even drew cartoonish images of, had actually committed the murders. Whether this represented a genuine dissociative delusion, a calculated psychological defense mechanism, or an attempt to evade responsibility remains debated among mental health professionals. Psychiatrists who examined Miyazaki diagnosed him with dissociative identity disorder and/or schizophrenia, serious mental illnesses that potentially could have affected his legal culpability.​

However, despite these psychiatric evaluations and his obvious severe mental illness, the Japanese court determined that Miyazaki was nonetheless sufficiently aware of the consequences of his actions and therefore legally responsible for his crimes. On April 14, 1997, after seven years of trials and legal proceedings, Miyazaki was sentenced to death by hanging. The Supreme Court would uphold his death sentence in January 2006, more than sixteen years after his original arrest, ending the extraordinarily prolonged legal process. By that point, Miyazaki had spent nearly two decades in Japanese custody awaiting the execution of his sentence.​

On June 17, 2008, Justice Minister Kunio Hatoyama signed Miyazaki’s death warrant, and at age 45, Tsutomu Miyazaki was hanged. The timing of his execution carried particular significance, it came just nine days after a mass stabbing in Akihabara, Tokyo’s famous electric district and the epicenter of otaku culture, in which a young man killed seven people and injured ten others. Some observers suggested that the government’s decision to carry out Miyazaki’s execution at this particular moment was calculated to reassure a frightened public in the aftermath of another shocking act of violence, though this remains speculative.​

Remarkably, even facing his own death, Miyazaki displayed no acknowledgment of his victims or their families. In a letter written to a monthly magazine in July 2006, he called capital punishment “an inhuman criminal act” and expressed concern about his own suffering during the execution process, describing how “the trapdoor opens and I drop through it” and how “every prisoner is forced to feel terror after being told of their execution by prison staff.” There was no expression of sympathy for Mari Konno, Masami Yoshizawa, Erika Namba, or Ayako Nomoto, the four children whose lives he had stolen. There was no acknowledgment of the immeasurable suffering of their families. His only concern was his own pain, his own fear, a final and complete manifestation of the profound narcissism and absence of empathy that had characterized his entire existence.​

The legacy of Tsutomu Miyazaki extends far beyond the details of his individual crimes. His case forced Japanese society to confront uncomfortable truths about the dangers of social isolation, the role of extreme media consumption in the psychology of troubled individuals, and the tragic consequences of family dysfunction left unchecked by professional intervention. Some blamed his crimes on the “otaku” subculture and anime, yet this represented a fundamental misunderstanding of causality, millions of young people consumed anime without becoming serial killers. Rather, Miyazaki’s crimes resulted from a catastrophic convergence of biological deformity, emotional neglect, social rejection, untreated mental illness, and access to increasingly extreme sexual and violent imagery, all culminating in a psychological state so fractured that it could only express itself through the ultimate violation of human innocence.

The case also raised profound questions about the Japanese legal system, the nature of mental illness and criminal responsibility, and whether capital punishment represents justice or merely societal vengeance. Eighteen years passed between his arrest and his execution, a period of time that many argue left both Miyazaki and society suspended in a state of unresolved trauma. The families of his victims, denied any expression of genuine remorse and forced to endure decades of legal proceedings, found no closure or healing in the eventual execution of the man who had destroyed their lives. They simply saw another young life, one they loved and cherished, reduced to tragedy.

Tsutomu Miyazaki remains one of Japan’s most infamous criminals, his story a dark meditation on the fragility of the human psyche and the consequences of a society’s failure to recognize and intervene in profound psychological distress. His crime spree lasted barely thirteen months, yet its ripples continue to reverberate through Japanese culture and criminal justice history decades later. He was not a monster born from nothing, but rather a deeply disturbed individual whose mental illness, family trauma, social alienation, and access to extreme media created the psychological conditions for unimaginable violence. His case serves as a haunting reminder of what can occur when human suffering goes unaddressed, when isolation compounds shame, and when a troubled mind finds no avenue toward healing or redemption.