This manga is strange and problematic. In short, it features several teenage girls being se**** abused.
No, it features a bunch of teenage girls starting to learn about parts of themselves that they're not really comfortable with and in the process learning to deal with these newly-awakened feelings and impulses, while a deceptively-cute creature seeks to harvest their massive powers that are affected in various ways by those feelings.
Seriously though, if you find it "problematic", just leave and find something more up your alley to read. Don't go and declare it to others like you need to make sure others know it's bad, believe others don't already know the parts that you consider bad, and furthermore believe people are going to not read it just because of that far-from-novel statement. Seriously, just a page or two ago this thread was overwhelmed with people arguing back and forth about this. Everyone knows it's an extreme series, with a style of humor and general content that many will be uncomfortable with. That doesn't mean it shouldn't exist. It just means that it's not for everyone, and that's completely fine.