On May 1, 1963, 16-year-old Yoshie Nakata disappeared while walking home from school in Sayama, Saitama, Japan. A ransom note was delivered to her family that night, demanding ¥200,000 be brought to a location near her home. Her sister attempted to deliver fake money under police surveillance, but the man who approached her grew suspicious and fled before police could apprehend him. On May 4, Nakata's body was found buried on a farm; police determined she had been raped and murdered. Media coverage criticized police for failing to catch the suspect during the ransom exchange, drawing comparisons to a separate kidnapping case that had occurred a month earlier.
Police investigation focused on employees of the nearby Ishida Pig Farm, where the owner's family and most employees were burakumin, a Japanese minority group that has historically faced discrimination. Kazuo Ishikawa, a 24-year-old employee, was arrested on an unrelated charge and, after weeks of isolation, confessed on June 20, 1963, to the kidnapping and murder. Ishikawa and his supporters later stated that the confession was coerced through threats and isolation, and that he was illiterate and unfamiliar with legal rights, circumstances they say police exploited. Ishikawa was convicted of aggravated murder, rape, and kidnapping and sentenced to death; his sentence was later commuted to life imprisonment with the possibility of parole.
Supporters and defense teams have raised extensive challenges to the conviction, including questions about handwriting analysis of the ransom note, the circumstances under which a pen belonging to Nakata was found in Ishikawa's home only after two prior extensive police searches failed to locate it, inconsistencies between Ishikawa's confession and forensic evidence (including absence of expected bruising, blood traces, and ankle marks), and the lack of any witness placing Ishikawa and Nakata together despite the confession describing them walking together in a busy area during a local festival. The case became entangled in a dispute between the Buraku Liberation League and the Japanese Communist Party over Ishikawa's legal representation, with his lawyer resigning in 1975 over political disagreements.
Ishikawa was released on parole in 1994 after 31 years of imprisonment. He continued to seek a retrial to clear his name, stating in 2002 that he wanted the "label of murderer" removed. He died on March 11, 2025, at age 86, while still pursuing a retrial. Human rights groups and lawyers have argued that Ishikawa's status as a burakumin influenced the courts' assumption of his guilt, framing the case as an example of institutional discrimination within the Japanese legal system.