Japanese girl, 16, detained 18 days for alleged crime, develops eating disorder, dies weighing 20kg

A Japanese girl, known as Runa, passed away in December 2025, five months after she had been detained.

The 16-year-old was locked up for 18 days and was not allowed to see her mother during that time.

According to Japanese media, she developed post-traumatic stress disorder and an eating disorder after her release.

She passed away in December 2025.

Suspected assault

Runa’s mother, Yoko, was in charge of a home that cares for people with disabilities in Hyogo prefecture.

Runa worked there as well.

During an incident, two patients had gotten into a disagreement, and Runa had put her hand against a patient’s chin to stop them from biting the other.

She was arrested four months later on suspicion of assault, during which she was held for 18 days.

She was barred from meeting her mother and detailed what she felt and went through during this time in a journal, as reported by Kansai TV.

She wrote that she “really didn’t do it”, and “I love you, Mommy, I can’t wait to see you.”

Her writings were reportedly smudged by tears.

She also recounted what she was asked during questioning, including things like, “You did it, didn’t you? Tell the truth.” and “We don't want to shut down the facility, so don't cause your mother any trouble.”

Runa maintained her innocence.

The Japan Times reported that she vomited and collapsed, and was taken to a hospital for brief medical care before being released on non-prosecution.

Following her incarceration, she was diagnosed with post-traumatic stress disorder. She also developed an eating disorder.

Runa’s weight continued to drop, and she passed away five months later in December 2025 at 20 kilograms from extreme malnutrition.

Mother filed lawsuit

Yoko has since filed a lawsuit against the national and prefectural governments, seeking JPY$109,000,000 (S$888,617) in damages.

She claims Runa’s death was caused by illegal arrests and detention.

The first court hearing took place on Oct. 21, as reported by ABC TV.

Yoko asked to clarify the facts and basis behind the decision to detain her daughter.

Her claims include that Runa was subjected to 18 days of physical detention under an illegal and sloppy investigation, and said that she had been pressured to confess to the crime.

She suffered from extreme malnutrition and lost a significant amount of weight.

Meanwhile, the Hyogo Prefectural Police said that there was no illegality under the National Compensation Act in the police investigation and the handling of the detention facility.

They also pointed out that Runa did not die immediately after being released, but 5 months later. They questioned if there were other reasons such as pre-existing medical conditions.

They have asked for the claim to be dismissed.