A truck driver in Kishiwada, Osaka Prefecture, and his girlfriend were arrested Sunday on suspicion of attempting to kill the man's 15-year-old son by starving him.
Yasunobu Karasuno, 40, and Natsuyo Kawaguchi, 38, allegedly frequently beat the boy and stopped giving him regular food in June. He fell into a coma, was hospitalized in November and remains unconscious, police said.
Karasuno called an ambulance Nov. 2 after the boy fell into the coma, believing he was dead. The boy was extremely underweight and near death when paramedics arrived, and part of his body had necrotized. They notified the police of his condition.
He weighed 24 kg at the time and had symptoms of hypoglycemia and brain atrophy, police said.
The boy began living with Karasuno and Kawaguchi around spring 2001 after his father divorced his mother. Karasuno's other son, 14, joined them in 2002.
The couple, who were also living with the woman's 15-year-old son, allegedly began beating the two Karasuno children in June 2002, burning them with cigarettes and shoving their heads into dirty bath water.
The younger son fled to his mother's home shortly afterward.
Karasuno's elder son, who was held to a starvation diet beginning around June, grew so weak that within two months was unable to walk, the police said.
They said teachers visited the home after the boys stopped going to school, but the couple refused to let them see their students.