Police in Tokyo received an emergency call at 1:35pm local time on September 1, 2025. A caller reported a woman covered in blood had collapsed on a street. A man had fled the scene.
Ms Bang Ji Won, a 40-year-old South Korean woman, was found with her throat slashed in a residential area in Setagaya ward. The attack happened about 500 metres northeast of Komazawa University station on the Tokyu Den-en-toshi line.
She was working in the area during the attack. Paramedics rushed her to hospital unconscious. Doctors later pronounced her dead.
The attacker was Park Yongjun, a 30-year-old South Korean man. He had been in a relationship with Ms Bang. Park flew from South Korea to Japan and confronted her for trying to break up with him.
Police arrested Park three hours later at Haneda Airport on suspicion of murder. Officers found blood on his clothing during detention. He exercised his right to remain silent. Park refused to answer questions during the investigation.
Ms Bang had previously sought help from Japanese authorities about Park’s violent behaviour. On August 29, 2025, she reported to police that her boyfriend had flown from South Korea to Japan and attacked her. This happened after she attempted to break up with him.
Park had arrived in Tokyo earlier in August. Following Ms Bang’s complaint, police officers visited her home on August 30. They warned Park to stay away from her. Officers also instructed him to find different accommodation during his stay in Japan.
Police advised Ms Bang to stay at an acquaintance’s home for her safety.
Park told police he planned to go sightseeing in Osaka before returning to South Korea. However, officers spotted him near Ms Bang’s home on August 30. This prompted police to issue another warning against contacting her.
Police officers accompanied Park to Haneda Airport. He had a plane ticket to South Korea. He went through security procedures. Authorities were unable to maintain surveillance of his whereabouts after this point.
Despite the police escort and security measures, Park managed to return. He carried out the fatal attack on Ms Bang.
Investigations are ongoing.
