The dead were identified as the couple’s son, Shunsuke, 10, and daughters, Miyu and Mina, both 6, and Mio, 3.
“Their father found them dead and reported it to police,” a police spokesman said.
Junko Fuchi confessed to the police she had killed the children. The police were reported as saying at least one child bore marks indicating strangulation.
Junko Fuchi was taken to a hospital because her wrist was bleeding, according to media reports. She allegedly told the police she cut herself with a kitchen knife.
According to the police, she made emergency calls to police on Friday and Saturday asking for “advice about family issues,” but the police judged her request was “incomprehensible.”