Unless the police are being pitted against the main characters, then they're even more competent than any security force in existence.@Purplelibraryguy Teachers and the police being useless are the common trope in manga.
It's hinted in bonus chapter 18.5 and chapter 23, but readers might've missed the former since a bonus chapter means there would be a slight delay in release, and interpreted the latter as standard bullying while overlooking the extra layer of her being a tsundere brat, hence the confusion in the comments.The MC is smart when it comes to Nishimura, he has a counter for everything.
Also, when did Kasahara started liking the MC?