The Ikeda school massacre was a school stabbing and mass murder that occurred in Ikeda, Osaka Prefecture, Japan, on 8 June 2001. Mamoru Takuma, a 37-year-old ex-convict with a history of mentally disturbed and anti-social behavior, stabbed eight students to death and seriously wounded fifteen others in a knife attack that lasted several minutes. Takuma was sentenced to death in August 2003, and executed in September 2004. As of 2025, it is currently the deadliest school attack in Japanese history.