The more I read this manga the more I realized something. The girls in this manga aren't the real monsters. The real monsters are the ones who are reading it.
If the phrase "monster harem" is something that interests you, then what more questions could you have? Does story matter? Does character development matter? Does any of this matter?
Monster Musume is a niche pick for people who are already too deep and can't go back. That being said, it's not the worst, but it's probably what you'd expect
If you're not ready, then don't read it, but if you are, then have fun