<figure id="attachment_470197" aria-describedby="caption-attachment-470197" style="width: 2171px" class="wp-caption alignnone"><a href="#" data-ident_hash="e0ac1879"><img src="https://res.cloudinary.com/fridaydigital/image/private/t_article_image/wpmedia/2026/06/587ceb76874c3cc94c9a16333477c65c.jpg" alt=""></a><figcaption id="caption-attachment-470197" class="wp-caption-text">Ms. C, the mother of the victim, Yari, who held a press conference in January of the year following the incident</figcaption></figure>
 The murder of Yari Yoshimatsu (21) by Juvenile A (15 at the time) at the Fukuoka shopping complex “MARK IS Fukuoka Momochi.” Following [Part 1], we will now look at Juvenile A’s family background and the thoughts of Yari’s mother.
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 [ <a href="https://friday.kodansha.co.jp/article/470185">Part 1: Fukuoka Stabbing Case: &#8220;Victim’s Mother to the Juvenile Offender and His Family&#8221;—A Confession of Anger]</a>
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 Ever since the incident, Ms. C, the bereaved mother, has been haunted by one question: Why did her daughter have to be stabbed to death with a kitchen knife by a complete stranger?
 Boy A had never met Yari; he brutally murdered her—a woman he had never even seen before—by chance. The full details of the case only came to light after the criminal trial began.
 Juvenile A grew up in a small town facing the azure waters of Kagoshima. Contrary to the idyllic atmosphere of the town, his upbringing at home was extremely complicated.
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 From birth, he exhibited noticeable speech delays and hyperactivity, and by the age of two or three, he had been diagnosed with a developmental disorder and was attending a special needs facility. Normally, with guidance from specialists there, and with his family respecting his unique traits while warmly watching over and supporting him, he should have been able to adapt to his surroundings to some extent.However, in his case, the opposite occurred: his violent tendencies increased with each passing year, and his speech and behavior became increasingly incoherent. The cause lay in his poor home environment.
 Both parents were born in 1977; they married as teenagers and had three children: an eldest daughter, an eldest son, and the second son, Boy A.
 The father was rarely home, spending most of his time working or partying, and when he did return, he repeatedly committed domestic violence. He also had a reputation for womanizing and had taken on mistresses.
 Meanwhile, the mother, B-ko, also lacked any sense of responsibility as a parent. She did almost no housework and spent her days indulging her desires and going out to have fun. The house was a hoarder’s den, and the children were left in a state of neglect.
<h2> “Like getting shot in the face with an air gun”</h2>
<figure id="attachment_470196" aria-describedby="caption-attachment-470196" style="width: 2593px" class="wp-caption alignnone"><a href="#" data-ident_hash="4a238296"><img src="https://res.cloudinary.com/fridaydigital/image/private/t_article_image/wpmedia/2026/06/2f2a9728b5ca6d075963ce7636b53c97.jpg" alt=""></a><figcaption id="caption-attachment-470196" class="wp-caption-text"> The perpetrator, Boy A</figcaption></figure>
 Due to these family dysfunctions, the eldest son became stressed and took it out on Boy A, who was four years his junior. After the incident, when I met with Boy A at the Fukuoka Detention Center, he told me the following:
 “To me, my older brother feels like an enemy. I feel nothing but resentment and anger.He would always subject me to all kinds of violence for no reason. He’d suddenly punch me, choke me, or shoot me in the face with an air gun. He’d often hit me with objects, too. It pissed me off, but since there’s a four-year age gap, I couldn’t fight back—I just had to take it.”
 The violence perpetrated by the eldest son even extended to sexual acts. He forced Boy A to assist him in masturbating by making him lick his penis and anus.
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 Boy A’s mother, B-ko, also sexually abused him. She engaged in lewd acts such as flaunting her sexual intercourse with her husband in front of the children night after night, making Boy A lick her breasts, assisting him with masturbation, and engaging in deep kissing.
 Who exactly was B-ko? When I interviewed my paternal grandfather, who lives at my family home in Kagoshima, he offered the following explanation.
 “B-ko had a disability too. When she took her grandson (Boy A) to the hospital and he was diagnosed with a developmental disorder, they apparently told her she had one as well. From what I could see, B-ko’s symptoms were more severe.The house was so cluttered you couldn’t even walk through it, and no matter what you said to her, she couldn’t give a proper response. She couldn’t even cook a proper meal. The yard was overgrown with weeds. She just couldn’t manage to do anything, even if she tried.”
 Because B-ko barely even prepared meals at home, Boy A reportedly spent his days licking pancake mix to stave off his hunger.
 It’s not hard to imagine how Boy A, who was already struggling to cope with life, ended up shouldering even more complex problems due to this home environment.
 By the time he entered elementary school, Boy A had begun taking out his frustrations on those around him. He would lash out at people and smash things indiscriminately&#8230; Because he had been sexually abused, he experienced an early sexual awakening, and by the time he was in second grade, he was indulging in masturbation almost every day.
<div data-friday-nextpage-lead=" The shocking details revealed by the juvenile offender, Boy A"></div>
<figure id="attachment_470195" aria-describedby="caption-attachment-470195" style="width: 2500px" class="wp-caption alignnone"><a href="#" data-ident_hash="793712fb"><img src="https://res.cloudinary.com/fridaydigital/image/private/t_article_image/wpmedia/2026/06/a017e0caf9119cc47e6729799c0161ba.jpg" alt=""></a><figcaption id="caption-attachment-470195" class="wp-caption-text">The late Yari. She was said to have a personality that everyone liked (courtesy of the bereaved family)</figcaption></figure>
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 It was in third grade that Boy A’s propensity for violence became particularly evident. During an interview at the detention center, he told me the following:
 “One day, my dad suddenly took me to [recreational facility] ‘R.’ When we got there, my dad’s Filipino mistress was there.Without really understanding why, I was made to play with her. That’s when something snapped inside me. Until then, I’d had this feeling that I should at least try to be a good kid. But I started thinking that it was pointless, and that I might as well just do whatever I wanted.”
 Later, his father divorced his mother and began living with his mistress. He had abandoned his family.
 Boy A’s erratic behavior became increasingly out of control. If his older brother told him, “Don’t skip school,” he would fly into a rage and pull out a kitchen knife. He would snap at store clerks who tried to correct him. He would brag to female teachers about reading pornographic magazines. He would expose his genitals to members of the opposite sex…
 He explained to me that at the time, “the bad side of me came out.” Even when he committed the crime, he said it was “the bad side of me” that did it, but perhaps he was using that to describe a state where he had lost all self-control.
<h2> Two Triggers for the Incident</h2>
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 Rather than worrying about Boy A, B-ko decided to have him admitted to a medical facility, as if to get rid of a nuisance. However, because he continued to cause problems there as well, he was transferred to other facilities.
 Over the seven years from third grade through seventh grade, Boy A was shuffled from one institution to another: a child psychological treatment facility, a psychiatric hospital, a child self-reliance support facility, a medical juvenile detention center, and a juvenile detention center. After entering the juvenile detention center, he was “dosed” with psychotropic drugs, but this did not constitute fundamental treatment.
 Boy A committed the murder when he was in his third year of junior high school. Two days after his temporary release from the juvenile detention center, he carried out the violent act at “MARK IS Fukuoka Momochi.”
 There were two major direct triggers.
 One was that while he was in the facility, doctors had “dosed him heavily” with psychotropic drugs to suppress his violent behavior. After being released from the juvenile detention center, he was supposed to manage his medication on his own, but Juvenile A was not the type who could control himself.
 Therefore, to prevent withdrawal symptoms, the doctor should have gradually reduced his dosage before the provisional release. However, they did not do this and instead abruptly stopped his medication before releasing him. As a result, when he left the juvenile detention center, Boy A was in an abnormal mental state.
 The second issue concerns the placement of Juvenile A after his provisional release. Initially, his mother, B-ko, was supposed to take him in. However, partly because she was living with a new partner, B-ko suddenly refused this arrangement before his provisional release. Juvenile A was deeply traumatized by this.
 Normally, a treatment conference should have been held to find the most suitable placement for Juvenile A and to work with relevant parties to guide him through the rehabilitation process. However, he was placed in a probation and parole facility without holding such a conference.
<div data-friday-nextpage-lead=" Four Issues Identified by the Bereaved Family"></div>
<figure id="attachment_470200" aria-describedby="caption-attachment-470200" style="width: 1301px" class="wp-caption alignnone"><a href="#" data-ident_hash="39a249ae"><img src="https://res.cloudinary.com/fridaydigital/image/private/t_article_image/wpmedia/2026/06/0c98d94180cc9ad941d2e9191cf0aa37.jpg" alt=""></a><figcaption id="caption-attachment-470200" class="wp-caption-text">A strange sculpture made of clay by Boy A when he was in elementary school</figcaption></figure>
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 The rehabilitation facility in Tagawa City, Fukuoka Prefecture, tended to house many of the old-school “yankee” types, and it specialized in rehabilitating such youths. Boy A, on the other hand, was of a completely different type. Suffering from drug withdrawal symptoms, it was inevitable that he would come to hate this environment and want to escape it.
 As a result, Boy A escaped from the rehabilitation facility after just one day. The very next day, after wandering the streets of Fukuoka City, he committed the brutal murder of Ms. Yari using a kitchen knife he had shoplifted.
 Ms. C, Ms. Yari’s mother, only learned the details of the incident through the trial and media reports. Upon hearing this, she became even more determined to ensure that Ms. Yari’s death was not in vain by uncovering the factors that led to the incident and holding those responsible to account.
 After numerous discussions with her lawyer and conducting her own investigation, Ms. C identified the following four major issues:
 1. The security measures at the commercial facility, which prioritized the evacuation of customers over the rescue of the victim
 2. The store’s management system, which allowed Juvenile A to easily steal a kitchen knife
 3. The government’s inadequate response, including abruptly stopping medication prescriptions and failing to hold treatment coordination meetings
 4. The responsibility of Juvenile A and his mother, B-ko
 Regarding points 1 and 2, the commercial facility took action. It began holding regular security training sessions at its affiliated facilities and strictly enforced management measures, such as requiring stores handling knives and similar items to display merchandise in locked cases. Additionally, the facility installed a monument of an angel within the premises to commemorate the victims.
 Regarding point 3, a lawsuit seeking compensation from the government is currently pending.
 And the ruling issued by the Fukuoka High Court in this case pertains to point 4. Ms. C sought damages from both the juvenile and B-ko, arguing that not only had they failed to fulfill their responsibilities as guardians, but they had also created the conditions that led Juvenile A to commit the crime.
<h2> “I made up my mind,”</h2>
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 In the trial, it was uncertain whether an order to pay damages would be issued not only against the juvenile A, who committed the crime, but also against B. While it was a fact that she had provided inappropriate care, the boy had been under the facility’s supervision from the middle grades of elementary school onward. In the first trial, these circumstances were taken into account, and it was ruled that B had no obligation to pay.
 The ruling was overturned in the second trial held at the High Court. The judge ruled that “B lacked a sense of responsibility as a parent,” acknowledging that even though Boy A had been placed in a facility, B still bore parental responsibility. Consequently, the court ordered her to pay damages jointly and severally with her son.
 Ms. C stated the following:
 “I believe B bears at least some responsibility for Boy A turning out the way he did. It wasn’t just that she did nothing; she actively exerted a negative influence on Boy A. It is clear that B is partly to blame for the incident.
 Yet, when we first met, B-ko immediately rejected us, saying, ‘We don’t have any money.’ No matter what her reasons might be, that is simply not an acceptable way to speak.At that moment, I made up my mind. If she truly had no money, I would make her understand our suffering regardless. If she refuses to pay, I intend to pursue her, even if it costs me money.”
 One thing that stands out in this trial is that Boy A’s father has not been sued.
 The plaintiffs wanted to hold the father accountable alongside B-ko. However, because custody was granted to B-ko at the time of the divorce, the father was no longer the legal custodial parent, so they could not sue him.
 This is a contradiction that cannot be overlooked. The father also bears responsibility for warping Boy A’s personality. If he is exempt from that responsibility simply because he is divorced, it would mean that by relinquishing custody, he could simultaneously shed responsibility for the abuse. Unfortunately, this is the limit of current law.
 The damages awarded in this case amount to approximately 54 million yen. How do Boy A and B-ko view this?
 Boy A is currently incarcerated in a juvenile detention center; he has no money to pay, and it is hard to imagine that he will be able to properly adapt to society after his release and pay such a large sum in damages. According to someone close to him, the ruling has not resonated with Boy A at all; rather, there is a high possibility that it will drive him into a state of “self-destructive despair.”
 As for B-ko, she filed an appeal after the verdict was handed down. She likely believes she bears no responsibility and has no obligation to pay. Consequently, the final decision has been referred to the Supreme Court.
 Yari’s mother says the following:
 “I don’t think either Juvenile A or B-ko are truly confronting the incident. Everything they say and do is strange. They’ve been doing nothing but insulting and hurting me and my murdered daughter, Yuri. Why must she suffer this fate when she was just living an ordinary life?
 It’s so frustrating, so frustrating. The reason I’m pursuing this civil lawsuit is to make them confront the incident, even just a little. I believe that if they do confront it, their words will change. That is what I can do for Yari.”
 What decision will the Supreme Court make?
 Even if they are ordered to pay, will Juvenile A and B-ko comply?
 If not, what must be done to make them confront the incident and elicit those “different words”?
 The significance of the questions raised by an incident that occurred six years ago is profound.

 Kota Ishii (Nonfiction Writer)

 Courtesy of the bereaved family, Kyodo News, and others

 In August 2020, a 21-year-old woman was stabbed to death by a juvenile at a commercial facility in Fukuoka. A court ruling ordered the juvenile’s mother to pay damages, finding her partially responsible for the crime. Nonfiction writer Kōta Ishii interviewed the bereaved family and others. This is the [Part 2] of that series.

&#8220;Let them understand our suffering,&#8221; the bereaved family wailed&#8230; Fukuoka Stabbing Case: The Mother&#8217;s Guilt for &#8220;Sexually Abusing the Juvenile Offender&#8221;

“Let them understand our suffering,” the bereaved family wailed… Fukuoka Stabbing Case: The Mother’s Guilt for “Sexually Abusing the Juvenile Offender”

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