I live about a 10 minute drive from the city center where the huge prefectural police HQ is located and when I called them to report that the neighbor directly above me was beating the hell out of his girlfriend, they had to call me back 2-3 times to 1) confirm my address, and 2) ask for waypoints and landmarks. Then, nearly 90 minutes later, the cops finally arrived and it was a couple guys in plain clothes wearing crocs and backpacks who told me it was late and the fighting seemed to stop and they didn’t wanna bother the guy by knocking on his door. They told me to give em another call if it started again and then left. I guess your experience with police will vary based on where you live. Maybe they respond faster in Tokyo.