In August 2021, 18-year-old high school student Wano-ka from Sumida Ward, Tokyo, went missing after saying she was meeting a friend. Her body was found days later in Yamanashi Prefecture. Shohei Komori, 27, and his wife Izumi Komori, 28, confessed to killing her out of jealousy and resentment. The case was solved rapidly within three days due to quick family reporting and advanced forensic technology including surveillance cameras and the N System. Shohei and Izumi had met Wano-ka via social media two years earlier. Shohei had feelings for Wano-ka, which caused jealousy in Izumi after their recent marriage. The murder occurred after a failed meeting and a wrong turn during a planned trip to return Wano-ka home. Shohei strangled and stabbed Wano-ka with Izumi's assistance. Both were arrested, confessed, and sentenced to long prison terms in 2023. The case highlights dangers of social media interactions and swift police response.
Country: Japan
State/Province: Tokyo, Japan
City/Region: Sumida
Incident Type: Murder
Relationship Status: Married
Relationship Duration: Approximately 3 months (marriage)
Incident Date: Aug. 28, 2021
Relationship Origins:
Relationship Stages:
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Red Flags:
Motives:
Relationship Outcomes:
How the relationship or connection began.
Approximately 3 months (marriage)
Important relationship phases recorded for this case.
Reported red flags or early concern points.
Contributing factors and possible motives from the available sources.
2021-08-28
Recorded relationship or case outcome.
English labels are shown first. Original-language titles are preserved for source verification.
ゆっくりミステリー事件簿 · Original language: Japanese
Tokyo Sumida High School Girl Murder Case
Jealousy
The case centers on jealousy and resentment within a newlywed marriage, exacerbated by the husband's prior online relationship with the victim. The wife's jealousy and dependent relationship with her husband contributed to their joint involvement in the murder. The victim was an unrelated high school girl who had limited in-person contact with the husband but was perceived as a romantic rival.
Police rapidly identified suspects through surveillance footage and the N System automatic license plate reader. The suspects confessed promptly, enabling quick body recovery and arrest within three days. Court proceedings recognized the husband's primary role and the wife's dependent personality disorder. Sentences of 23 and 18 years imprisonment were handed down in 2023.
Initial uncertainty about the suspects' identities was resolved quickly by forensic tracking. The wife's diminished responsibility claim introduced some complexity in court but did not obscure the main facts.
Wano-ka left home on August 28, 2021, to meet a friend but was picked up by Shohei Komori. After a calm initial meeting and deleting contact info, the suspects attempted to return her home but got lost. Shohei's jealousy escalated to murderous intent. They took Wano-ka to a shed in Yamanashi Prefecture, strangled and stabbed her, then abandoned the body. Police tracked the vehicle via surveillance and N System, found the suspects in Nagano Prefecture, and recovered the body in Yamanashi.
High risk due to escalating jealousy, dependent personality dynamics, and prior violent behavior by the husband. The involvement of social media contact and rapid escalation to lethal violence indicates significant danger in similar contexts.
The case underscores the dangers of social media relationships, especially involving minors and adults. Rapid family reporting and advanced forensic technology are critical for swift resolution. Jealousy and dependent personality dynamics can escalate quickly to lethal violence.
The victim's failure to return home and missing cram school attendance were early signals prompting family concern and police action.
Surveillance footage showing the victim entering a vehicle voluntarily and the vehicle's route tracked by the N System were key clues.
Surveillance camera footage and automatic license plate reader data were strongest evidence types.
Neighbors described the victim as kind and polite; classmates reported the husband's occasional violent outbursts; the wife's prior abusive marriage and social isolation were noted. No direct eyewitnesses to the crime were reported.
Court proceedings clarified the wife's diminished responsibility claim and the husband's primary role. Sentencing details emerged in 2023. No information on appeals is available.
Exact details of the suspects' communications and the wife's psychological state remain partially unclear. The full extent of planning versus impulsivity is not fully resolved.