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Asama-Sansō incident

SOLVED1972Asama Sansō lodge, near Karuizawa, Nagano Prefecture, Japan3 SOURCESUPDATED JUL 2026
Illustrative

The Asama-Sansō incident was a hostage crisis and police standoff at a mountain lodge below Mount Asama, near Karuizawa in Nagano Prefecture, Japan, lasting from February 19 to February 28, 1972. It followed an internal purge within the United Red Army (URA), a radical leftist group, in which URA leaders Tsuneo Mori and Hiroko Nagata directed the beating deaths of eight members and one non-member at a compound in Gunma Prefecture; six additional members were tied to trees outside and froze to death. On February 16, 1972, police arrested Mori, Nagata, and six others at or near the compound, while five other armed members fled on foot toward Karuizawa.

On February 19, 1972, these five fugitives — Kunio Bandō, Masakuni Yoshino, Hiroshi Sakaguchi, Jirō Katō, and Saburō Katō — took refuge in a vacation lodge called Asama Sansō, owned by Kawai Musical Instruments Manufacturing. Inside, they found Yasuko Muta, the 31-year-old wife of the lodge's caretaker, and took her hostage at gunpoint, barricading themselves inside the concrete-and-wood building. Police surrounded the lodge, initially waiting for a surrender, then cutting electricity and broadcasting appeals from relatives of the radicals, without success.

On February 28, 1972, police launched an assault using a crane with a wrecking ball, ladders, chainsaws, and high-pressure water hoses. The radicals fired on police and threw homemade explosives during the operation. Two police officers, Inspector Shigemitsu Takami (42) and Superintendent Hisataka Uchida (47), were shot and killed, and fifteen other officers were injured. A civilian observer who entered the area without permission was also fatally shot, reportedly by the radicals. Police officer Masahiro Endō was shot in the eye by Bandō and lost the eye but survived. By 6:15 p.m. that day, all four remaining radicals were taken into custody and Muta was rescued; she was cold but uninjured and told police she had not been mistreated, though she had been tied to a bed for most of the standoff. That evening, Bandō's father died by suicide in Ōtsu, reportedly despondent over his son's actions.

Public broadcaster NHK aired live continuous coverage of the February 28 assault for over ten hours, drawing average ratings of 50.8% and a peak of 89.7%. The five radicals were charged with two murders, one attempted murder, obstructing police duties, firearms violations, and illegal confinement. Four received long prison sentences; Sakaguchi was sentenced to death, and in 2013 the Supreme Court of Japan rejected his appeal for a retrial. In 1975, the Japanese government released Bandō, flying him to Libya in response to demands during a Japanese Red Army embassy siege in Kuala Lumpur; he remains at large. After the incident, weekly gossip magazines publicly criticized hostage Yasuko Muta, misrepresenting her comments about her captors, after which she stopped speaking publicly about her ordeal and continued working in Karuizawa. The incident is credited with contributing to a broader decline in popular support for leftist student movements in Japan.

Key facts

Victims
Yasuko Muta, Masahiro Endō, Shigemitsu Takami, Hisataka Uchida
Date
1972
Location
Asama Sansō lodge, near Karuizawa, Nagano Prefecture, Japan
Case status
solved

Case timeline

  1. 1971-02-17

    Keihin group raids a gun shop in Mooka, Tochigi Prefecture, acquiring firearms and ammunition.

  2. 1971-02-22

    Red Army Faction begins a series of bank, post office, and school robberies known as 'Operation M', continuing through July 1971.

  3. 1971-12

    Joint military exercises held between the Keihin Group and Red Army Faction; combined leadership conference held December 20 at the Haruna base.

  4. 1972-02

    URA leaders Tsuneo Mori and Hiroko Nagata direct an internal purge at a Gunma Prefecture compound, resulting in deaths of eight members by beating and six by exposure.

  5. 1972-02-16

    Police arrest Mori, Nagata, and six other URA members; five armed members flee toward Karuizawa.

  6. 1972-02-19

    Five URA fugitives take refuge in the Asama Sansō lodge near Karuizawa and take Yasuko Muta hostage, beginning the standoff.

  7. 1972-02-25

    Police tactical units begin preparations for an assault on the lodge.

  8. 1972-02-27

    Police use a pitching machine to bombard the lodge with rocks overnight.

  9. 1972-02-28

    Police storm the lodge; two officers are killed, a civilian observer is fatally shot, and the four remaining radicals are taken into custody by 6:15 p.m.; Muta is rescued.

  10. 1975-08-08

    Japanese government releases Kunio Bandō and flies him to Libya in response to a Japanese Red Army embassy siege in Kuala Lumpur.

  11. 2013-06-24

    Supreme Court of Japan rejects Hiroshi Sakaguchi's appeal for a retrial, leaving him on death row.

Best coverage

No approved coverage links are attached yet.

People

  • Tsuneo Mori

    CHARGED

    URA chairman charged in connection with directing the internal purge that preceded the standoff; arrested February 16, 1972.

  • Yasuko Muta

    VICTIM

    Lodge caretaker's wife taken hostage during the ten-day standoff; rescued uninjured on February 28, 1972.

  • Kunio Bandō

    CONVICTED

    One of five URA members involved in the hostage-taking; convicted, later released by the Japanese government in 1975 and flown to Libya; remains at large.

  • Masahiro Endō

    VICTIM

    Police officer shot in the eye during the assault; lost the eye but survived.

  • Shigemitsu Takami

    VICTIM

    Police inspector (42) shot and killed during the February 28, 1972 assault on the lodge.

  • Jirō Katō

    CONVICTED

    URA member involved in the hostage-taking, aged 19 at arrest; sentenced to 13 years hard labor.

  • Saburō Katō

    CONVICTED

    URA member involved in the hostage-taking, aged 16 at arrest; sent to reform school.

  • Hiroko Nagata

    CHARGED

    URA vice-chairman charged in connection with directing the internal purge that preceded the standoff; arrested February 16, 1972.

  • Hisataka Uchida

    VICTIM

    Police superintendent (47) shot and killed during the February 28, 1972 assault on the lodge.

  • Masakuni Yoshino

    CONVICTED

    One of five URA members who barricaded themselves in the lodge with the hostage; sentenced to a long prison term.

  • Hiroshi Sakaguchi

    CONVICTED

    One of five URA members who took hostage; sentenced to death; 2013 Supreme Court appeal for retrial rejected.

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

Places

Asama Sansō lodge, near Karuizawa, Nagano Prefecture, Japan

36.2891, 138.6221

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Common questions

What happened to the victim?
A ten-day hostage standoff at a mountain lodge near Karuizawa, Japan, ended on February 28, 1972, when police stormed the building; two officers were killed and the hostage, Yasuko Muta, was rescued unharmed.
Where did the crime happen?
Asama Sansō lodge, near Karuizawa, Nagano Prefecture, Japan.
Who was convicted?
Kunio Bandō (One of five URA members involved in the hostage-taking; convicted, later released by the Japanese government in 1975 and flown to Libya; remains at large.), Jirō Katō (URA member involved in the hostage-taking, aged 19 at arrest; sentenced to 13 years hard labor.), Saburō Katō (URA member involved in the hostage-taking, aged 16 at arrest; sent to reform school.), Masakuni Yoshino (One of five URA members who barricaded themselves in the lodge with the hostage; sentenced to a long prison term.), and Hiroshi Sakaguchi (One of five URA members who took hostage; sentenced to death; 2013 Supreme Court appeal for retrial rejected.).
What is the current status of the case?
Status: solved.
More cases in Japan

Sources

  1. ENCYCLOPEDICAsama-Sansō incidentWikipedia · 2026-07-10
  2. PRESSContemporaneous coverage — search.japantimes.co.jpsearch.japantimes.co.jp · 2026-07-10
  3. PRESSContemporaneous coverage — findarticles.comfindarticles.com · 2026-07-10

Record history

First published
JUL 11, 2026