Casepin
Back to cases

Case file

Ōmuta murders

SOLVED2004Ōmuta, Fukuoka, Japan3 SOURCESUPDATED JUL 2026
Illustrative

Between 18 and 20 September 2004, four members of the Kitamura-gumi (北村組), a yakuza gang based in Ōmuta, Fukuoka, Japan, affiliated with the Dōjin-kai crime syndicate, killed four people. According to Wikipedia's account, Mami Kitamura had borrowed money from a 58-year-old woman, Sayoko Takami. On 18 September 2004, Mami, her husband, and her two sons strangled Sayoko and shot her 18-year-old son Tatsuyuki and his 17-year-old friend Junichi Hara. The perpetrators placed the three victims' bodies in a car, which they then dumped into the Suwa River in Ōmuta.

On 20 September 2004, the same group strangled Sayoko's 15-year-old son, Jōji. His half-naked body was found the following day, 21 September. When police arrested Mami on 22 September, she confessed to the killing of the other three victims, and police subsequently recovered the car containing their bodies from the Suwa River.

The other participants named in the killings were Mami's husband, Jitsuo Kitamura, the leader of the Kitamura-gumi; Takashi Kitamura, her son from a previous marriage; and Takahiro Kitamura, her second son. Takashi and Takahiro were both former sumo wrestlers, known respectively as Kyokuryūjin and Miikezan, under the family name Ishibashi. As police closed in on the group, Jitsuo attempted to kill himself with a handgun. Takashi escaped from police custody but was recaptured. Jitsuo maintained that he had committed the murders alone, but police regarded Mami as the primary offender.

The defendants were reported as disruptive during their trials. On 17 October 2006, Mami and Takahiro were sentenced to death. Jitsuo and Takashi received death sentences on 28 February 2007. On 25 December 2007, the Fukuoka High Court upheld the original sentences for Mami and Takahiro; Takahiro reportedly shouted "Merry Christmas!" in court following the ruling. On 27 March 2008, the Fukuoka High Court also upheld the original sentences for Jitsuo and Takashi.

Separately, Wikipedia notes that Takashi Kitamura had a prior conviction for a June 2000 incident in which he and six associates beat an 18-year-old boy with a bokken (wooden sword) before he was dropped into an irrigation canal and drowned; Takashi was sentenced to three years and six months in prison for that offense.

Two additional sources are listed as corroborating references cited in the Wikipedia article's bibliography but their content could not be independently retrieved for this dossier.

Key facts

Victims
Jōji Takami, Junichi Hara, Sayoko Takami, Tatsuyuki Takami
Date
2004
Location
Ōmuta, Fukuoka, Japan
Case status
solved

Case timeline

  1. 2000-06

    Takashi Kitamura, along with six associates, beat an 18-year-old boy with a bokken; the victim was dropped into an irrigation canal and drowned. Takashi was later sentenced to three years and six months in prison for this offense.

  2. 2004-09-18

    Mami Kitamura, her husband, and her two sons strangled Sayoko Takami and shot her son Tatsuyuki and his friend Junichi Hara; the bodies were placed in a car and dumped in the Suwa River in Ōmuta.

  3. 2004-09-20

    The group strangled Sayoko Takami's 15-year-old son, Jōji.

  4. 2004-09-21

    Jōji's half-naked body was found.

  5. 2004-09-22

    Police arrested Mami Kitamura, who confessed to the killing of the other three victims.

  6. 2004-11

    Takashi Kitamura escaped from police custody during questioning but was recaptured, per Wikipedia's cited Japan Times reference dated November 14, 2004.

  7. 2006-10-17

    Mami Kitamura and Takahiro Kitamura were sentenced to death.

  8. 2007-02-28

    Jitsuo Kitamura and Takashi Kitamura were sentenced to death.

  9. 2007-12-25

    The Fukuoka High Court upheld the death sentences for Mami and Takahiro Kitamura.

  10. 2008-03-27

    The Fukuoka High Court upheld the death sentences for Jitsuo and Takashi Kitamura.

Best coverage

No approved coverage links are attached yet.

People

  • Jōji Takami

    VICTIM

    15-year-old son of Sayoko Takami, strangled on 20 September 2004; body found 21 September 2004.

  • Takashi Kitamura

    CONVICTED

    Mami Kitamura's son from a previous marriage, former sumo wrestler known as Kyokuryūjin; sentenced to death on 28 February 2007, upheld 27 March 2008; also had a prior conviction related to a June 2000 killing.

  • Junichi Hara

    VICTIM

    17-year-old friend of Tatsuyuki Takami, shot on 18 September 2004.

  • Sayoko Takami

    VICTIM

    58-year-old woman strangled on 18 September 2004; had lent money to Mami Kitamura.

  • Mami Kitamura

    CONVICTED

    Sentenced to death on 17 October 2006 for the murders of Sayoko Takami, Tatsuyuki Takami, Junichi Hara, and Jōji Takami; sentence upheld by Fukuoka High Court on 25 December 2007. Regarded by police as the main offender.

  • Tatsuyuki Takami

    VICTIM

    18-year-old son of Sayoko Takami, shot on 18 September 2004.

  • Takahiro Kitamura

    CONVICTED

    Mami Kitamura's second son, former sumo wrestler known as Miikezan; sentenced to death on 17 October 2006, upheld 25 December 2007.

  • Jitsuo Kitamura

    CONVICTED

    Leader of the Kitamura-gumi; sentenced to death on 28 February 2007; sentence upheld by Fukuoka High Court on 27 March 2008.

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

Places

Ōmuta, Fukuoka, Japan

33.0119, 130.4462

View on the map

Common questions

What happened to the victim?
In September 2004, four members of the Kitamura-gumi, a yakuza gang in Ōmuta, Fukuoka, Japan, killed four people, including a woman to whom the family owed money and her three sons, in a case tied to a debt dispute.
Where did the murders happen?
Ōmuta, Fukuoka, Japan.
Who was convicted?
Takashi Kitamura (Mami Kitamura's son from a previous marriage, former sumo wrestler known as Kyokuryūjin; sentenced to death on 28 February 2007, upheld 27 March 2008; also had a prior conviction related to a June 2000 killing.), Mami Kitamura (Sentenced to death on 17 October 2006 for the murders of Sayoko Takami, Tatsuyuki Takami, Junichi Hara, and Jōji Takami; sentence upheld by Fukuoka High Court on 25 December 2007. Regarded by police as the main offender.), Takahiro Kitamura (Mami Kitamura's second son, former sumo wrestler known as Miikezan; sentenced to death on 17 October 2006, upheld 25 December 2007.), and Jitsuo Kitamura (Leader of the Kitamura-gumi; sentenced to death on 28 February 2007; sentence upheld by Fukuoka High Court on 27 March 2008.).
What is the current status of the case?
Status: solved.
More cases in Japan

Sources

  1. Ōmuta murderswikipedia · Wikipedia · 2026-07-07
  2. Contemporaneous coverage — search.japantimes.co.jpnews · search.japantimes.co.jp · 2026-07-07
  3. Contemporaneous coverage — fsinet.or.jpnews · fsinet.or.jp · 2026-07-07