It's a fun anime to watch and you should not take it seriously. This show tends to take the piss out of the genre.
I wouldn't be so quick to classify this as a harem series. While yes there is more than two love interesting wanting this dudes D for some reason. The show focuses on two love interest the most. Akane and Guri.
Akane . With Akane she is a Nice, Pretty and the main love interest of the MC. As soon as she realizes that the MC had kissed another girl she legit tries to kill him.
Guri . While being my favorite character she has the less amount love interest and character development of the two. She is an angel who cosplay's as a wanna be demon. She also has the Kiss note ( Yes it's just as it sounds ) Honestly i feel she more time on screen. And for also being a character who cosplay's she gets very little of screen time of her changing outfits.
Would love to see more of this. The MC does fall into the stereotype of anime MC. I also feel this anime gets more hate than it deserves. Not great but would recommend it.