According to the Metropolitan Police Department, around 7:30 pm on the 20th, a passerby reported that "someone is bleeding" in Shibuya Ward, Tokyo.
The injured were a mother in her 50s and a daughter in her teens who were believed to have been stabbed with a knife.
Both are conscious.
The Metropolitan Police Department arrested a girl, believed to be in her teens, on the spot on suspicion of attempted murder, and is investigating the details of the situation at the time.
The site is an area densely populated with houses and restaurants about 50 meters northeast of Shinsen Station on the Keio Inokashira Line.