The woman fatally stabbed on a street in the city of Fukuoka had told police several times before the incident that she had issues with her ex-boyfriend, police said Tuesday.
The police identified the woman who died Monday in hospital after being stabbed near JR Hakata Station as Miki Kawano, 38.
Kawano told the police a few months ago that she had been harassed by her ex-boyfriend, investigative sources said. Police said they cannot contact him.
The man involved in the stabbing is believed to be in his 30s to 50s and was wearing a black jacket.
According to the investigative sources, Kawano, who lived in the neighboring city of Nakagawa, was seen walking and then quarreling with a man in an area about 200 meters west of the station where a number of office buildings and hotels are located.