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North Kanto serial kidnappings and murders

UNSOLVED1986Ashikaga City, Tochigi Prefecture and Ota City, Gunma Prefecture, Japan2 SOURCESUPDATED JUL 2026
Illustrative

Overview

Between 1979 and 1996, five girls aged four to eight were abducted within a roughly 20 km (12 mi) radius near the border of Tochigi and Gunma prefectures. The incidents occurred in Ashikaga or Ota. Four victims were found dead; the fifth child has never been found.

The five cases

On 3 August 1979, a five-year-old girl disappeared while playing near a shrine in Ashikaga; her body was found six days later beside the Watarase River. On 17 November 1984, another five-year-old girl disappeared from a pachinko parlor; her body was found in March 1986 in a nearby field. On 15 September 1987, an eight-year-old girl disappeared from her home in Ota; her body was recovered in November 1988 near the Tone River. In 1990, a four-year-old girl was abducted and killed in the case known as the Ashikaga murder case. On 7 July 1996, a four-year-old girl disappeared from a pachinko parlor and was never found.

Investigation and miscarriage of justice

In 2007, investigative journalist Kiyoshi Shimizu began examining similarities among the cases and found serious problems with the conviction of Toshikazu Sugaya in the 1990 Ashikaga case. The reported problems included a confession that did not fit the physical timeline, eyewitness testimony that contradicted it, and flawed DNA procedures. Sugaya said a detective had coerced his confession. New DNA testing led to his release in 2009, and a court acquitted him at a 2010 retrial.

Continued impunity

Authorities acknowledged the wrongful conviction in the Ashikaga case, and officials publicly discussed the possibility that the five incidents were connected. No one has been arrested for the five abductions. Shimizu has reported DNA evidence that he says points to an unnamed person, while police have said that person's DNA does not match the earlier Ashikaga results. The cases remain unresolved.

Key facts

Victims
Mami Matsuda, Maya Fukushima, Tomoko Oosawa, Yukari Yokoyama, Yumi Hasebe
Date
1986
Location
Ashikaga City, Tochigi Prefecture and Ota City, Gunma Prefecture, Japan
Case status
unsolved

Case timeline

  1. 1979-08-03

    Five-year-old Maya Fukushima disappears near a shrine in Ashikaga; her body is found six days later beside the Watarase River.

  2. 1984-11-17

    Five-year-old Yumi Hasebe disappears from a pachinko parlor.

  3. 1986-03-08

    Yumi Hasebe's body is found in a field 1.7 km from her home.

  4. 1987-09-15

    Eight-year-old Tomoko Oosawa disappears after leaving her home in Ota.

  5. 1988-11-27

    Tomoko Oosawa's body is found abandoned by the Tone River.

  6. 1990

    Mami Matsuda is killed in what becomes known as the Ashikaga murder case.

  7. 1996-07-07

    Four-year-old Yukari Yokoyama disappears from a pachinko parlor and is never found.

  8. 2007

    Journalist Kiyoshi Shimizu begins investigating similarities between the five cases.

  9. 2009

    New DNA testing leads to Toshikazu Sugaya's release from prison.

  10. 2010

    A retrial finds Sugaya innocent of the Ashikaga murder.

  11. 2010

    Shimizu reports DNA test results he says connect an alleged perpetrator to the Ashikaga case, and provides this to police, but no arrest is made.

  12. 2011

    Then-Prime Minister Naoto Kan urges police to catch the true culprit in a Diet session.

Best coverage

No approved coverage links are attached yet.

People

  • Mami Matsuda

    VICTIM

    Victim of the 1990 Ashikaga murder case.

  • Toshikazu Sugaya

    EXONERATED

    Originally convicted in the Ashikaga murder case; released in 2009 after new DNA testing and found innocent in a 2010 retrial.

  • Maya Fukushima

    VICTIM

    Five-year-old victim of the 1979 kidnapping and murder in Ashikaga.

  • Tomoko Oosawa

    VICTIM

    Eight-year-old victim of the 1987 kidnapping and murder in Ota.

  • Yukari Yokoyama

    VICTIM

    Four-year-old who disappeared in 1996 from a pachinko parlor and was never found.

  • Yumi Hasebe

    VICTIM

    Five-year-old victim of the 1984 kidnapping and murder.

Roles reflect public records and court outcomes at the time of writing — supporting citations are on file under Sources.

Places

Ashikaga City, Tochigi Prefecture and Ota City, Gunma Prefecture, Japan

36.3416, 139.4483

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Common questions

What happened to the victim?
Since 1979, five young girls aged four to eight were abducted—and in four cases murdered—in a 20 km radius spanning Tochigi and Gunma prefectures in Japan. Investigative reporting later revealed that a man convicted for one of the murders was wrongly imprisoned, and the case remains unsolved despite official acknowledgment that it is likely the work of one perpetrator.
Where did the murders happen?
Ashikaga City, Tochigi Prefecture and Ota City, Gunma Prefecture, Japan.
What is the current status of the case?
Status: unsolved.
More cases in Japan

Sources

  1. ENCYCLOPEDICNorth Kanto serial kidnappings and murdersWikipedia · 2026-07-10
  2. PRESSContemporaneous coverage — japantimes.co.jpjapantimes.co.jp · 2026-07-10