Saitama woman, carer for reclusive sister with mental illness sentenced to 3 years and 6 months in prison

From The Saitama Shimbun via Yahoo! Japan

November 1 2026

SAITAMA – A 53-year-old company employee was sentenced to three years and six months in prison on Oct. 30 by the Saitama District Court for causing the death of her younger sister, who had a mental disorder and lived with her, through assault.

Presiding Judge Kenji Koike handed down the sentence for causing death through injury. Prosecutors had sought a six-year prison term.

In explaining the reasons for the ruling, Judge Koike described the circumstances leading up to the incident. The defendant began living with her younger sister around October 2021 after their mother moved away in what appeared to be an effort to avoid the younger sister. The younger sister had become socially withdrawn due to her mental disorder.

The judge said the defendant had accumulated considerable stress from caring for her sister and managing her daily life. He also noted that she had continued pursuing procedures to secure a place for her sister in a group home rather than abandoning her, saying there were “grounds for sympathy.”

However, the judge criticized the defendant for assaulting her sister to free herself after the younger woman clung to her, then leaving her unattended until the following day. He said the assault on the head, a vital part of the body, was “extremely dangerous.”

The judge concluded that a prison sentence without suspension could not be avoided.

After delivering the sentence, Judge Koike told the defendant: “Your sister engaged in troublesome behavior toward you, and I understand that you experienced difficulties. I can also understand that you tried to care for her rather than abandoning her.”

He added: “There was also an aspect of her having no choice but to rely on you, and it is regrettable that she had to die in this way.”

The judge continued: “I think you have had no time to live for yourself until now. After returning to society, please think about how you can live your own life.”

According to the ruling, the defendant assaulted her younger sister, then 43, at their home in Koshigaya, Saitama Prefecture, on Aug. 16 last year, punching her in the head several times and inflicting injuries including bruising to the right side of her head.

The younger sister died on Aug. 21 from a brain herniation.