Two 17-year-old Ibaraki Prefecture girls have been arrested for allegedly confining, beating and cutting off the earlobes of a 26-year-old woman who had "bad-mouthed" them.
The two girls confined the woman at the home of their 22-year-old male friend in Kita-Ibaraki between April 4 and 9, police alleged.
During the period, the girls assaulted the woman, whose name was withheld, by kicking and punching her, they said.
They also cut the woman's earlobes with scissors and pressed an electric hair curler against her body, inflicting injuries and burns that will require six months of medical treatment, police said.
The victim used to work part-time with one of the two girls at a drive-in restaurant in Mito. The two girls were identified only as an unemployed resident of Mito and a part-time worker in Kita-Ibaraki.
The woman attempted to escape from the house on April 5 but was forcibly brought back by the girls. They then stripped her of her clothes so she would not escape.
Wearing the clothes of the male friend, she ran away again on the night of April 9 when she had been left in the home alone. She returned to Mito and notified police, according to investigators.
The girls told police they assaulted the woman because she had "bad-mouthed" them. Police also plan to question the girls' male friend, who was not identified.