The attack
On the morning of June 8, 2001, Mamoru Takuma entered Osaka Kyoiku University Ikeda Elementary School in Ikeda, Osaka Prefecture. He attacked children and teachers inside first- and second-grade classrooms before staff members subdued him.
Eight children were killed: seven girls and one boy. Contemporary reporting and later court coverage consistently record 15 injured survivors — 13 students and two teachers.
The case shocked Japan in part because it happened inside an elementary school, a place generally assumed to be secure. It immediately prompted national discussion about school access, emergency procedures and the protection of pupils.
Investigation and criminal responsibility
Takuma was arrested at the school. Police subsequently expanded the criminal allegations to cover all eight deaths and the injuries to students and teachers.
A major issue at trial was whether he could be held criminally responsible. Defense lawyers argued that his mental condition prevented full responsibility. Psychiatric evaluations presented during the proceedings concluded that he retained the capacity to understand his actions and could be held legally responsible. The Osaka District Court accepted that position.
Crime by Region treats that finding narrowly: it was a legal determination about this defendant. It should not be read as suggesting that mental illness generally causes violent crime.
Trial and sentence
Takuma admitted the killings. On August 28, 2003, the Osaka District Court convicted him and imposed the death penalty. The judgment followed a trial lasting roughly 20 months and found him criminally responsible for the murders.
Defense lawyers filed an appeal, but Takuma withdrew it in September 2003. The withdrawal caused the death sentence to become final without the ordinary appellate process continuing.
Execution
On September 14, 2004, Takuma was executed at the Osaka Detention House. The execution occurred less than a year after his sentence became final, unusually quickly by Japanese practice at the time.
The Justice Ministry publicly confirmed that two executions had taken place but, following its practice then, did not identify the prisoners. Japanese and international news organizations identified Takuma as one of the two men executed that day.
Aftermath
The attack became a reference point in Japan's debate over school security. Schools across the country reconsidered open-campus practices, visitor access and emergency response. Memorial events continued to center the eight children who were killed and the effects on classmates, families and staff.
The case is legally closed: Takuma was convicted of the murders, his death sentence became final after he withdrew his appeal, and the sentence was carried out in 2004.
Timeline
June 8, 2001: eight children are killed and 15 students and teachers are injured at Osaka Kyoiku University Ikeda Elementary School.
June–July 2001: police expand the case to cover all deaths and injuries; Takuma remains in custody.
2002–2003: the Osaka District Court hears evidence including psychiatric assessments addressing criminal responsibility.
August 28, 2003: Takuma is convicted and sentenced to death.
September 2003: he withdraws the appeal filed by his defense team, finalizing the sentence.
September 14, 2004: Takuma is executed at the Osaka Detention House.
Current status
The case is solved and adjudicated. Mamoru Takuma was convicted of killing eight children and injuring 15 other people, and his sentence was carried out in September 2004. No unresolved question remains about the identity of the attacker.