Kanae Kijima was sentenced to death on April 13, 2012 by a lay judge panel at the Saitama District Court, north of Tokyo. The court convicted her of murdering three men she had met through internet marriage-hunting and dating sites in 2009, and of a series of lesser fraud and theft offenses. All three men died of carbon monoxide from burning charcoal briquettes, a method widely used in suicides in Japan, and the court found that she had given each of them sleeping pills first. Prosecutors said she had taken money from the men on the promise of marriage and killed them so they could not ask for it back.
There was no confession, no witness to any of the deaths, and no direct physical link between Kijima and the act of killing. She has denied the murders from the start. The case rested on circumstantial evidence: her purchases of sleeping pills and charcoal, the money that moved from the men to her, and the fact that she was with each man shortly before he died. The trial lasted 100 days, the longest in Japan's lay judge system up to that time. The Tokyo High Court upheld the death sentence in 2014 and the Supreme Court rejected her last appeal in 2017.
The Japanese press called the case the "Konkatsu Killer" case, after konkatsu, the word for marriage hunting, and also used the old phrase "poison woman." Much of the coverage dwelt on her looks and her weight. Scholars and writers have since used the case to examine pretrial publicity, the burden of proof in lay judge trials, and the way Japanese media treat women accused of crimes. From death row she has written a blog, magazine essays and a novel.
Kijima was born in 1974 in Hokkaido, Japan's northern island, and grew up in Betsukai, a dairy farming town in the island's far east, according to a 2021 Bunshun Online excerpt from the Bessatsu Takarajima book on death row prisoners. Her father worked as an administrative scrivener, a licensed preparer of official documents, and she was said to have been raised strictly. The journalist Taeko Ishii, who reconstructed her life in a long series for the magazine Weekly Bunshun in 2024 and 2025, wrote that she was one of four children.
Ishii interviewed people who had known her as a child. A former elementary school classmate said that Kijima would deny wrongdoing even when caught, and once blamed the classmate for something she had not done; the classmate grew up thinking of her as someone to fear. Others remembered a dreamy, distant look in her high school years and an air of cool contempt for those around her, though Ishii noted that such impressions are often formed in hindsight. Ishii also wrote that her behavior grew more troubled as she entered junior high school and that she became increasingly isolated.
After graduating from a local high school, Kijima moved to Tokyo at about 18. She enrolled at Toyo University but withdrew soon afterward over unpaid tuition, according to the Takarajima account. She then worked at a dating club and entered paid arrangements as the mistress of wealthy men. AFP, reporting her sentence in 2012, also described her past as a paid mistress and said she had claimed to have worked as a nurse and a piano teacher. At 28 she was arrested for fraud involving internet auctions, an early sign, in the Takarajima account, of a pattern of deceiving people online.
By 2009 Kijima was presenting herself to men as a woman of means and refinement. Testimony at her trial, as summarized in the Takarajima account, described a false profile: she said her father was a professor at the University of Tokyo and that she herself was a piano teacher or a food coordinator. Ishii, drawing on the trial, wrote that she also claimed a link to the imperial family, said her father was a lawyer, and said she taught piano for a well-known music school. She lived in an expensive apartment in Tokyo and drove imported cars while keeping up relationships with several men at once.
Ishii reported that prosecutors questioned her in court about paying cooking school fees soon after two of the deaths.
According to the Takarajima account, from 2008 into 2009 she used a marriage-hunting website to approach more than 20 single men with offers of marriage and to take their money. Ishii's research led her to describe more fraud counts than murder counts in the indictments, and theft as part of the core of the case. Ishii wrote that Kijima bought the charcoal used in the deaths through online shopping and posted blog entries boasting of a lavish life paid for by money she obtained from men.
Other men connected with Kijima also died, and those deaths were never charged. The Takarajima account says that a 70-year-old man in Matsudo, Chiba Prefecture, who had given her more than 70 million yen, died in the bathroom of his home in 2007. A weekly magazine, cited by AFP in 2012, reported that she had emailed a 70-year-old lover to say her parents had died in a plane crash and that she needed money to study music in the United States, and that he was later found dead at home. Japanese prosecutors were reported by AFP to suspect her of killing as many as five more men she had met through online marriage sites. None of these deaths was ever charged. They remain suspicions and are not part of her convictions.
Takao Terada, 53, was a company employee who lived in Ome, in the western part of the Tokyo metropolitan area. AFP reported that he was found dead in his home in January 2009, with burning briquettes left there. According to Philip Brasor's 2012 analysis of the trial in The Asia-Pacific Journal, two of the three deaths took place in near identical charcoal settings and were first ruled suicides. The Takarajima account states that in three of the deaths linked to Kijima, the man had either sent her money before he died or she withdrew cash soon afterward. The trial court convicted her of his murder.
Kenzo Ando, 80, was a pensioner who lived in Noda, Chiba Prefecture. Ishii reported that he too met Kijima through a matching site and began a relationship with her, and that soon after they met he gave her 800,000 yen for her education and other costs, after which she kept asking for more. AFP reported, in its account of the verdict, that she had worked as his home helper. On May 15, 2009, by Ishii's account, she took his cash card from his house and withdrew almost everything in his account, about 1.88 million yen. A few hours after she left, the house caught fire and burned to the ground with him inside.
The fire was first treated as an accident, Brasor wrote. At trial, prosecutors showed surveillance camera footage of Kijima visiting his home hours before the fire and argued that she had set it. AFP reported that she was caught on camera withdrawing money with his card and that she testified he had asked her to do it.
Yoshiyuki Oide, 41, was an office worker from Chiyoda Ward in central Tokyo. He built plastic models as a hobby and kept a website about model tanks, as well as a personal blog. He met Kijima through a matching site and began seeing her, believing they would marry. According to Ishii, she asked him to help with her education costs and he gave her 4.7 million yen; AFP reported that he had transferred 5 million yen to her account shortly before his death.
On August 5, 2009, about 20 hours before his body was found, Oide wrote on his blog that he was marriage hunting, that he had met his partner's family, and that he was setting off on a three-day trip with her before the wedding, J-CAST News reported in 2010. He wrote that she had asked him to bring a small local gift, and that he had bought sweets for her in Akihabara. Earlier posts had hinted at a new relationship.
On August 6, 2009 he was found dead in the back seat of a rental car in a monthly parking lot in Fujimi, Saitama Prefecture. A charcoal stove with briquettes sat in the front footwell, and the cause of death was carbon monoxide poisoning. It looked like a suicide, but there was no car key in the vehicle, Ishii wrote, and AFP reported that no keys were in the ignition. An autopsy found sleeping pills in his blood; J-CAST reported a high concentration of a sleeping drug. Kijima, then 34, was the last person known to have been with him.
Oide's death was the one that first drew police attention. The Saitama Prefectural Police looked into the woman he had been seeing and found that other men who had known her had died. Kijima was arrested in Noda in September 2009 on fraud charges, Ishii reported. Ishii, who later visited the place, described a street of identical houses where one stood empty with its intercom cut. The Takarajima account gives the arrest date as September 5, 2009; other accounts give a later day in September.
While she was held on the fraud charges, Japanese media linked her to several men she was said to have had relationships with, and some of that coverage, Brasor wrote, implied before any murder charge that she was responsible for their deaths. During interrogation she remained almost completely silent, he wrote. On February 1, 2010 the Saitama police re-arrested her, then 35, on suspicion of murdering Oide. J-CAST News reported that physical evidence was scarce and that the high level of a sleeping drug in his body, together with his own blog posts about the planned marriage and trip, led investigators to conclude that his death was not a suicide. His blog stayed online and drew more than 1,800 comments, most of them messages of mourning.
Arrest warrants followed for the deaths of Terada and Ando, and she was indicted for three murders. Police said she held several prescriptions for the type of sleeping pills found in the men, AFP reported.
The three murder counts were joined with the fraud, attempted fraud and theft counts and tried together before a lay judge panel at the Saitama District Court, under the system that since 2009 has placed citizens on the bench with professional judges in serious criminal cases. Brasor described the general rule: a panel of six lay judges and three professional judges, with a death sentence requiring a majority that includes at least one professional judge. The presiding judge was Kazuyuki Okuma.
The trial opened in January 2012 and ran for 100 days. It heard 63 witnesses, AFP reported. Public interest was intense: more than 1,300 people lined up for the 49 seats open to the public on the day of the verdict.
The prosecution's case, as reported by Kyodo and AFP, was that each man died of carbon monoxide poisoning, that Kijima had prepared the briquettes and stoves found at each scene, that she had drugged each man with sleeping pills, and that she was with each of them until shortly before his death. Records of her purchases of sleeping pills and charcoal and the transfers of money to her accounts were central. Prosecutors pointed out that one of the men had no charcoal on his hands, which in their view showed he had not lit the fire himself, Brasor wrote. On the motive, they argued that she took money from the men under the false pretense of marriage and killed them when they were likely to demand it back.
Ishii described one moment from March 2, 2012, when a prosecutor questioning Kijima asked whether she had killed people to pay for cooking school, his voice shaking; his words, she wrote, were less a question than a statement of disbelief. In Ishii's account Kijima kept lying on the stand, to the visible frustration of the presiding judge and the prosecutor, and at times the gallery laughed.
The mother of one of the men testified and asked for the harshest possible punishment, Brasor reported. In closing, prosecutors asked for the death penalty. They used a metaphor that became the best known line of the trial: when you wake up and see snow on the ground that was not there the night before, you know it snowed, even though you did not see it fall. Brasor wrote that the image amounted to telling the judges that no further proof was needed.
Her lawyers argued that all of the deaths could have been accidents or suicides. Kyodo quoted the defense as saying that the prosecution's evidence "does not sufficiently prove that the defendant murdered the three men." They argued that the men may have taken their own lives after quarreling with her about ending the relationships, or died by accident. AFP reported that she herself said two of the men killed themselves because they were distraught at the thought of her leaving them. On the withdrawal from Ando's account, she testified that he had asked her to take out the money. Commentators, AFP noted, treated her ordinary appearance as a reason to doubt that account.
On April 13, 2012 the court found her guilty of all three murders and of the lesser charges and sentenced her to death, as the prosecution had demanded. Presiding Judge Okuma said, as quoted by Kyodo, that she had "repeatedly committed quite serious crimes that claimed the lives of three people" and that there was "no room for leniency as the defendant committed the crimes for selfish purposes." He said she "reiterated irrational excuses in court and did not show any remorse," and that she had acted to maintain an embellished way of life. In AFP's version, the judge said she had three times carried out extremely serious and vicious crimes in order to keep up a luxurious life without working.
She was the first woman sentenced to death by a lay judge court, according to the Takarajima account. The Japan Innocence and Death Penalty Information Center records her sentence as the 14th death sentence handed down by mixed panels of citizens and judges. Her lawyers said she would appeal.
On the day of the verdict, the Asahi Shimbun's digital edition published a handwritten statement of 12,328 characters that she had mailed in advance to a reporter at the paper, the psychiatrist and columnist Rika Kayama wrote later that year. It covered her upbringing, her life since her arrest and what she called messages to society, and it sharply criticized her interrogation and the prosecution.
The verdict prompted debate about how citizen judges should weigh a case without direct evidence. Brasor noted that an NHK special in April 2012 assembled six mock lay judges to reconstruct the deliberations; they concluded that the evidence was weak but that the motive was easy to believe. One of the real lay judges told reporters it had been "difficult to make a clear judgment" but that there was "no option but to convict," Brasor reported. He argued that heavy pretrial coverage had made the public likely to assume her guilt and had in effect moved the burden of proof onto the defense. The lawyer Tadataka Hayakawa, writing in President Online in 2013, cited her case among recent lay judge death sentences in a discussion of citizen judges' responsibility if a conviction proves wrong.
Kijima's lawyers appealed to the Tokyo High Court, which dismissed the appeal and upheld the death sentence on March 12, 2014, finding, as Kyodo summarized, that she had committed the crimes to maintain a luxurious lifestyle. The defense then appealed to the Supreme Court, again arguing that the men may have died by suicide or accident.
On April 14, 2017 the Supreme Court's Second Petty Bench rejected the final appeal and held that she had killed all three men, Kyodo and AFP reported. She was 42. She filed an objection to the ruling, which Weekly Gendai expected to be dismissed, and her death sentence became final in May 2017, according to Weekly Gendai and later Bunshun Online and Shukan Josei reports. Her defense team maintained that she was innocent and that the men had likely taken their own lives, AFP reported, citing NHK.
Kijima is held at the Tokyo Detention House in the Kosuge district of Tokyo, Shukan Josei reported in 2024. Japan carries out executions by hanging, and AFP noted when her sentence was upheld that the wait for execution can last years. Shortly before her sentence became final, she wrote in a long article for a weekly magazine, quoted in the Takarajima account, that after the sentence was final she would petition the justice minister for an early execution, saying she had no wish to die but lacked the confidence to go on living. In the same piece she said that many prisoners who request retrials do so only as a formality to delay execution. Weekly Gendai reported in May 2017 that she was said to want her sentence carried out quickly.
While in custody she has married more than once. AFP reported in April 2017 that she had married twice since her detention in 2009, and Kyodo reported that she had changed her surname to Doi. The Takarajima account refers to a third marriage in prison, to a magazine editor.
Kijima has kept writing throughout her imprisonment. In January 2014, while her appeal was pending, a blog titled "Kijima Kanae's Detention House Diary" began publishing her handwritten entries, posted by a supporter; the magazine Weekly Bunshun reported its launch in February 2014. In her early posts she sharply criticized the nonfiction writer Shinichi Sano and the writer Minori Kitahara, who had written about her trial. The weekly magazine Shukan Josei later dated the diary to December 2013 and said the posts stopped in May 2018. In 2024 she announced its return, and from September 2024 she sold paid installments of a prison diet diary, in which she described losing 30 kilograms on detention house food. Shukan Josei noted that the weight loss and its method rested only on her own posts.
In March 2015 the publisher Kadokawa released her semi-autobiographical novel, titled Raisan, Shukan Josei reported. Ishii wrote that Kijima began a long correspondence with an editor at Bungeishunju in November 2013, after ignoring an earlier letter, and told the editor she was writing a novel. Once she saw that her writing drew attention, Ishii wrote, she produced large numbers of letters, memoirs and stories, and seemed to lose interest in her own trial.
Her posts have also attacked the way she was covered. The Conversation, in an article on the case, wrote that she criticized the focus on her looks and her gender over the legal evidence, and that she wrote about prison food, snacks available in the detention house, dieting and the lay judge system.
Brasor, writing in 2012, called the "black widow" framing of the case blatantly sexist: much reporting asked how such an unattractive woman could be so successful at getting money from men, and some outlets used an old high school photograph of her. The Conversation described coverage that called her "ugly and fat" and that tied her alleged success with men to stereotypes about heavier women.
The novelist Asako Yuzuki took the case as the starting point for her novel Butter, published in Japan by Shinchosha in 2017. It follows a journalist who interviews a woman accused of killing men she met through dating sites, and it deals with fat-shaming and sexism in Japanese society. The English translation by Polly Barton was published by 4th Estate in 2024. The writer Masaru Sato, reviewing the novel in Weekly Gendai in 2017, noted how freely it departs from the real case: the fictional defendant comes from Niigata rather than Hokkaido, the deaths in the book are by other means, and she receives a life sentence at first instance. Kijima herself, The Conversation reported, called it "a vulgar book" on her blog and accused the author and publisher of theft.
In November 2024 Shukan Josei reported that Kijima, now using the surname Doi, was held under sentence of death at the Tokyo Detention House. No retrial request is listed for her by the Japan Innocence and Death Penalty Information Center. Chisako Kakehi, another woman sentenced to death for killing three men she had known, died in custody in Osaka in December 2024, AFP reported.
Guilt. Kijima has never admitted the killings. The courts at all three levels found that she drugged the men and lit the charcoal, but the finding rests on circumstantial evidence, and scholars and writers have continued to debate whether the lay judge process gave the defense a fair chance against intense publicity.
Other deaths. The 2007 death of a man in Matsudo and the other deaths that prosecutors were reported to suspect were never charged. They are suspicions only.
Arrest date. The Takarajima account gives September 5, 2009 for her first arrest; other accounts give a later date in September.
Her relationship with Kenzo Ando. AFP described her as his home helper; Ishii wrote that they met through a matching site and were in a relationship. Both are reported.
Money from Yoshiyuki Oide. Ishii gives 4.7 million yen; AFP gives a transfer of 5 million yen.
Finality date. Kyodo and AFP report the Supreme Court ruling on April 14, 2017; Weekly Gendai, Bunshun Online and Shukan Josei say the sentence became final in May 2017, after her objection. One Bunshun excerpt gives "April 4, 2017," which appears to be an error.
Blog start. Weekly Bunshun reported the first post as January 5, 2014; Shukan Josei dates the diary to December 2013.
Marriages. AFP and Shukan Josei report two marriages in custody; the Takarajima account refers to a third.
1974: born in Hokkaido; grows up in Betsukai.
About age 18: moves to Tokyo; enrolls at Toyo University and soon withdraws.
About age 28: arrested for internet auction fraud.
2007: a 70-year-old man in Matsudo who had given her large sums dies at home (never charged).
2008 to 2009: approaches more than 20 men through a marriage-hunting website.
January 2009: Takao Terada, 53, dies at his home in the Tokyo area.
May 15, 2009: Kenzo Ando, 80, dies in a fire at his home in Noda, hours after she withdraws money with his card.
August 5, 2009: Yoshiyuki Oide posts that he is about to take a premarital trip.
August 6, 2009: Oide is found dead in a rental car in Fujimi, Saitama.
September 2009: Kijima is arrested in Noda on fraud charges.
February 1, 2010: re-arrested on suspicion of murdering Oide; later indicted for three murders.
January 2012: lay judge trial opens at the Saitama District Court.
March 2, 2012: prosecutors question her about the cooking school fees.
April 13, 2012: convicted and sentenced to death; Asahi Shimbun Digital publishes her handwritten statement.
January 2014: her prison blog begins publishing entries.
March 12, 2014: Tokyo High Court dismisses her appeal.
March 2015: Kadokawa publishes her novel Raisan.
April 14, 2017: Supreme Court rejects her final appeal.
May 2017: the death sentence becomes final.
2017: Asako Yuzuki's novel Butter is published in Japan.
April 2024: Butter is published in English.
September 2024: she begins posting paid installments of a prison diary.