Japanese mom admitted guilt
A Japanese mother admitted killing her two children (Photo for illustrative purposes only) Simon Kan/Pexels

A Japanese mother has admitted killing her two children, but her trial is focused on whether her mental state left her criminally responsible. Prosecutors told Mito District Court that workplace grievances and worsening distress contributed to her belief that her children could not live without her and that they could be together in heaven if they died.

Akiko Ota, 42, admitted the charges at her first hearing on Wednesday, 14 October 2026. She is accused of fatally stabbing her son, Tsuguma, eight, and daughter, Riko, five, at the family's apartment in Mito, Ibaraki Prefecture, in July 2023. The indictment alleges that she stabbed each child in the neck with a kitchen knife.

Although Ota admitted the charges, the court must still decide whether she had the mental capacity to be held criminally responsible. Prosecutors argue that her mental condition influenced her actions but did not remove her responsibility. Her defence is seeking an acquittal, arguing that she was legally insane at the time.

Prosecutors Link Distress to Workplace Grievances

Prosecutors said Ota became deeply dissatisfied after management policies changed at the restaurant where she worked. Japanese broadcaster TBS News reported that prosecutors told the court she became distrustful of others, suffered from insomnia and developed suicidal thoughts.

According to the prosecution, Ota came to believe that her children could not survive without her. Prosecutors said she thought: 'My children cannot live without me. If we die, we can be together in heaven.' This remains the prosecution's account of her thinking, rather than a finding made by the court.

Prosecutors acknowledged that Ota's mental state affected her actions but argued that the effect was not significant enough to remove her criminal responsibility.

Defence Seeks Acquittal on Insanity Grounds

Ota's lawyers argue that she was in a state of insanity and could not stop herself from carrying out the killings. They are seeking an acquittal on the grounds that she lacked the mental capacity required for criminal responsibility.

Japanese television reports also described the defence's claim that Ota feared child welfare authorities might take her children away. This claim should remain attributed to the defence rather than presented as established fact.

Ota's admission to the acts described in the indictment does not settle whether she was legally responsible. The prosecution and defence disagree over how far her mental state affected her actions, and the court must assess the evidence. The trial therefore centres on criminal responsibility, rather than whether the alleged killings occurred.

Japanese Law on Insanity and Diminished Capacity

Article 39 of Japan's Penal Code distinguishes between legal insanity and diminished capacity. A person found legally insane at the time of an offence cannot be punished under the provision. If their capacity was diminished, the sentence must be reduced.

The question is not simply whether a defendant had a mental health condition. It is whether that condition impaired their ability to recognise the wrongfulness of their actions or act in accordance with that understanding.

Prosecutors say Ota's mental state influenced the killings but did not remove her criminal responsibility. Her lawyers argue that she was legally insane and should be acquitted. The court must decide which account is supported by the evidence.