A 20-year-old painter was arrested Wednesday on suspicion of committing three separate hit-and-run attacks on three young women Monday night, police said.
Junji Ogawa of Aoba Ward reportedly told investigators that he had intended to rob women carrying bags.
Police said Ogawa was drinking at a bar with his senior colleague Monday night and was told to go get 10,000 yen.
The suspect was reportedly upset over the request, and investigators suspect he may have attacked the women to vent his anger.
Ogawa told police he was aware that the victims may have been killed before he committed the acts, they said.
Ogawa was arrested for an alleged hit-and-run attack on a 20-year-old college student who was traveling home down a street at around 10 p.m.
Police said Ogawa drove past the woman and pulled the vehicle over. He then waited for her to pass and hit her from behind, police said. She suffered injuries that will require about two weeks of medical treatment, they added.
Investigators said he then hit two other women in a similar manner.
Police said the suspect has admitted to the allegations.
Ogawa reportedly did not rob the victims because he was scared of being identified. He returned to the bar after getting 10,000 yen from legitimate sources.
"I was always borrowing money from my mother. I did not want to bother her this time and came up with the idea to rob strangers," police quoted the suspect as saying.
Investigators added that he was unhappy with his older colleague's stiff attitude toward him.
Police arrested him at around 3:30 a.m. Wednesday after getting tips from witnesses.