<figure id="attachment_472582" class="wp-caption alignnone" style="width: 640px;" aria-describedby="caption-attachment-472582"><a href="#" data-ident_hash="302626ad"><img src="https://res.cloudinary.com/fridaydigital/image/private/t_article_image/wpmedia/2026/06/072565e80d1d155aeb44595e48d9e6a7.jpg" alt=""></a><figcaption id="caption-attachment-472582" class="wp-caption-text">The verdict for the defendant accused of stabbing her husband&#8217;s mistress in the head is drawing attention</figcaption></figure>
<h2>The defendant entered the courtroom with the stature of a model and long, beautiful hair</h2>
The first hearing for Aiko Kobayashi (58), who has been charged with assault for attacking a female acquaintance with a knife at a hotel in Tokyo&#8217;s Shinjuku Ward, was held at the Tokyo District Court on June 18.
&#8220;The incident took place at a restaurant inside the Rihga Royal Hotel Tokyo in Shinjuku Ward. At around 9 a.m. on April 10, Kobayashi attended a meal with her husband. There, she unexpectedly came face to face with Ms. A, the victim in the case, who had been having a long-term affair with her husband.
Kobayashi got into an argument with her husband on the spot and stabbed Ms. A in the back of the head with a knife, among other acts, and was arrested at the scene on suspicion of attempted murder. Ms. A suffered injuries that required two weeks to heal, while Kobayashi&#8217;s husband sustained minor injuries. At the time of her arrest, Kobayashi admitted to the act, saying, &#8216;That&#8217;s correct,&#8217; but stated, &#8216;I don&#8217;t remember,&#8217; when asked about her motive,&#8221; said a reporter from a national newspaper.
Kobayashi appeared in court wearing a gray sweatshirt and sweatpants. Because she was wearing a mask, her facial expression could not be seen. Perhaps as a result of her detention, gray hair was visible at the roots, but her model-like height and beautiful long hair were striking.
When she took the witness stand and was asked about her occupation by the judge, she replied, &#8220;I am unemployed and a full-time housewife.&#8221; She also admitted the allegations in the indictment, saying, &#8220;There are no mistakes in it.&#8221;
What emerged during the trial was a drama of love and hatred involving a middle-aged love triangle.
According to the prosecution&#8217;s opening statement, Kobayashi worked at an advertising company after graduating from university. She married her husband and gave birth to three children. However, her husband had affairs with multiple women, and she had struggled with his infidelity for many years.
After discovering the affair between her husband and Ms. A, Kobayashi and Ms. A communicated directly through LINE. Their exchanges continued to devolve into arguments, and Kobayashi eventually filed a lawsuit against Ms. A over the affair. As a result, Ms. A submitted a letter apologizing for continuing the relationship, and the two sides temporarily reached a settlement.
However, Ms. A allegedly continued to harass Kobayashi by making silent phone calls and engaging in similar behavior, causing Kobayashi to develop adjustment disorder and other conditions. Then, on the day of the incident, Kobayashi unexpectedly encountered Ms. A, leading to the tragedy.
According to Ms. A&#8217;s written statement, she wants the heaviest punishment possible and harbors strong feelings of resentment toward Kobayashi.
The first witness to take the stand as a character witness was the lawyer whom Kobayashi had consulted.
The lawyer explained that Kobayashi had been mentally exhausted from the harassment she received from her husband&#8217;s mistress. Referring to Kobayashi&#8217;s husband as an unusual husband, the lawyer testified that Kobayashi was an ordinary person who did not possess the emotional strength necessary to continue such a relationship.
According to the eldest son, who testified next, he had received a message from Kobayashi on the day of the incident that essentially said:
&#8220;Ms. A is here. Help me.&#8221;
<div data-friday-nextpage-lead="Both her husband and children defended the defendant."></div>
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<h2>The cruel words uttered by the unfaithful husband</h2>
&#8220;About a week before the incident, she repeatedly asked for help. I regret leaving my mother to suffer alone.&#8221;
The eldest son lowered his head as he spoke.
As the oldest child, he said that he had repeatedly tried to reason with his father, but admitted that &#8220;no one could stop him.&#8221;
However, he also testified that his father&#8217;s behavior had changed. The man now went straight home after work, and the son revealed:
&#8220;My father said things like, &#8216;Everything is my fault. I&#8217;m sorry to your mother.&#8217; He has also told Ms. A to withdraw the complaint.&#8221;
Finally, Kobayashi herself took the witness stand.
&#8220;Regardless of the reason, I would like to apologize for causing injury.&#8221;
She bowed her head before questioning began.
Answering questions from her lawyer, she recalled the events of that day. She and her husband had attended the gathering as hosts after being asked by the organizer. When she spotted Ms. A at the event, she said she wanted to leave immediately but endured the painful situation.
After the meal finally ended, she paid the bill and asked her husband, &#8220;What are you going to do now?&#8221;
His reply was blunt:
&#8220;Obviously, I&#8217;m going home with A.&#8221;
At that moment, she said:
&#8220;Twelve years of endurance collapsed.&#8221;
(Editor&#8217;s note: This appears to refer to the period during which her husband and Ms. A were involved in an affair.)
She continued:
&#8220;After that, my mind went completely blank, as though the film had been cut.&#8221;
She maintained that she had no memory of the moment when she attacked Ms. A with the knife.
When asked about her husband, she said:
&#8220;He came to visit me, and he cried his eyes out. During our 25 years of marriage, it was the first time he had ever cried for me. I believe him when he says that he will break up with her.&#8221;
The prosecution condemned the attack as dangerous and persistent and requested a prison sentence of two years.
The defense, meanwhile, argued that Kobayashi&#8217;s husband and Ms. A had maintained an affair for many years and that there were circumstances deserving of consideration, asking the court to hand down a suspended sentence instead.
How this middle-aged love triangle will ultimately end remains to be seen.
The verdict is scheduled to be delivered on July 1.

 On June 18, the trial of a woman who stabbed her husband’s mistress in the head with a knife began at the Tokyo District Court. Although her husband and eldest son defended her, the victim is seeking a conviction. The highly anticipated verdict is scheduled to be handed down on July 1.

Woman Accused of Attacking Husband’s Lover Receives Support From Family as Verdict Looms

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