Kirk here. I passed by this place on Friday afternoon, several hours after the incident. The only odd thing I noticed at the time was that there were TV cameras and people with media arm bands in the area:
— quote from Yomiuri — Kumamoto central police received an emergency call at around 9 a.m. Friday saying someone had been injured after being stabbed with a knife in the Chuo Ward of Kumamoto City. Officers rushed to the scene and found three women, believed to be in their teens to twenties, to be injured. All three were responsive when they were transported to the hospital by ambulance. The police apprehended a 29-year-old man nearby on suspicion of attempted murder. — end quote — https://japantoday.com/category/crime/man-arrested-after-3-women-stabbed-in-kumamoto-building
The RKK video report from which I took the screenshot said that the young women seem to have been attacked by their employer – an extremely bad boss.
RKK video report: https://newsdig.tbs.co.jp/articles/rkk/1070259?display=1