The ruling left her one appeal, to the Supreme Court of Japan. That court dismissed it in 2017, finding no reason to overturn the death sentence.
Published

No one saw Kanae Kijima kill anyone, and she never confessed. On March 12, 2014, the Tokyo High Court upheld her death sentence anyway, for the murders of three men she had met through websites for finding marriage partners.
The High Court backed the Saitama District Court, which had convicted her in 2012 and sentenced her to death as prosecutors had asked. Her lawyers argued that a guilty verdict built on circumstantial evidence alone was mistaken and that the men may have taken their own lives. The case went on to the Supreme Court of Japan, whose Second Petty Bench unanimously dismissed her final appeal on April 14, 2017, making the sentence final. By then she had married and taken the surname Doi.
Takao Terada, 53, was found dead in Tokyo in January 2009. Kenzo Ando, 80, died in his home in Chiba Prefecture that May, and three months later Yoshiyuki Oide, 41, was found in a rented car, poisoned by the fumes of burning charcoal briquettes. The courts found that Kijima had taken large sums of money from men she met on the sites by pretending to be in serious relationships, then killed these three to escape repaying them and to keep her lies from coming out, putting each man to sleep and burning briquettes to make his death look like suicide. The Supreme Court listed the evidence that carried the case: she had been alone with each man near the time and place of his death, she had obtained stoves and briquettes matching those found by the bodies before each killing, and neither suicide nor accident could explain any of the deaths. She was also convicted of three frauds, three attempted frauds and one theft against men she met through the same sites.
AFP said the three killings fell within eight months; the Supreme Court of Japan put the span at a little more than half a year.