; 1979 murder of Maya Fukushima: On 3 August 1979, five-year-old Maya Fukushima went missing while playing at a shrine near to her house in Ashikaga. Her body was found naked in a rucksack six days later abandoned next to the
Watarase river. ; 1984 murder of Yumi Hasebe: On 17 November 1984, five-year-old Yumi Hasebe went missing from a
pachinko parlor. Her body was found on 8 March 1986 in a field 1.7 kilometers away from her home. ; 1987 murder of Tomoko Oosawa: On 15 September 1987, eight-year-old Tomoko Oosawa left her house in Ota and went missing. Her body was found on 27 November 1988 abandoned by the
Tone River. ; 1990 murder of Mami Matsuda: The
Ashikaga murder case ; 1996 kidnapping of Yukari Yokoyama: On 7 July 1996, four-year-old Yukari Yokoyama went missing from a pachinko parlor. As the girl was never found, this is treated as a disappearance case. The following are used as reasoning behind the definition of this as a serial case: • All cases involved young girls between ages 4 and 8 • In three cases, the victim vanished from a pachinko parlor • In three cases, the body was found next to a river (the Watarase River in two) • Four cases happened on a Friday, weekend, or holiday All five crimes have not been resolved, with the culprit not arrested. The case has been given extensive media coverage, and has been brought up in the Japanese Diet multiple times, and was also addressed by then-prime minister
Naoto Kan, who appealed to the police to solve the case. Security camera footage of the culprit exists from the 1996 kidnapping case, and eyewitnesses from the Ashikaga case have stated that he strongly resembles the man they saw. In 2010 and 2011, Shimizu reported strong evidence that the perpetrator had been found, including DNA test results connecting him to the Ashikaga case (a 100% match to the results of new tests of the perpetrator's DNA) and video recordings of him talking to young girls and making them sit on his lap, and gave this information to the police, but no arrest was made. The reasoning given for the refusal to arrest the alleged perpetrator was that his DNA does not match that of the culprit previously found in the Ashikaga case. Shimizu professes that the DNA testing methods used in the Ashikaga case were flawed, and that arresting the perpetrator would require the prosecutor's office to acknowledge this. However, the same testing methods were also used in the
Iizuka case, in which the alleged culprit was executed in 2008 despite requests for new DNA tests and a retrial, and acknowledging that the testing methods were flawed would lead to a massive scandal around that case. Shimizu's investigations into the Iizuka case found the possibility that a large amount of the evidence was doctored, and he concludes that it was the amount, and not quality of the evidence which led to the conviction, and that overturning even one piece of evidence would have caused the prosecutor's case to fall apart. Additionally, when the mother of Mami Matsuda was informed by the police that they were no longer investigating her daughter's case due to the statute of limitations, she requested that they return her daughter's belongings, but they refused to return the shirt which has the true culprit's semen stains on it. They refused to give a straight answer as to why, and Shimizu suspects that this is because they are afraid that others might have the DNA of the true culprit tested by modern means, proving that the methods previously used returned wrong results. ==See also==