Here's a more detailed, less sensational, report.
https://www.nikkansports.com/general/news/201902270000970.html
"At 6:05 in the evening on the 27th, a man assaulted a woman, leaving her (age 27, a resident of Asaka city, Saitama) with light injuries on the face and hands in the parking lot of a building in Kabukicho 2-chome. According to the Shinjuku police, the assailant allegedly punched the woman and tried to rob her for her bag. The police are searching for the man as responsible for the alleged robbery causing bodily injury. The victim claimed that she and another woman (age 29) met the assailant whom they knew through a dating app. The assault took place as the man got infuriated while they were having a quarrel. The assailant claimed to be British on the dating app. He was described in his 30s, about 180 cm in height, wearing black jacket and black trousers at the time of the assault."
It's a bit of mystery to me as to why the rumor of "a Caucasian male attacked a random woman with a knife" spread so widely at the initial coverage of the incident, and no explanation was given when the original story was subsequently revised.