So, first off, if you like things with a solid developing plot, this is probably not the thing for you. Most of the time you can look at any individual volume and be fine without having read any other volume. Sometimes a story spreads out across 2, but that's pretty much it.
This manga is about Takahashi-san, a girl who appears normal on the outside, but really secretly loves to eavesdrop on these two boys in her class. Her character and that of the boys (Nara and Mikage) develops pretty steadily throughout the manga and you really see a lot about their insecurities and flaws, and
how they overcome them. There are a lot of jokes and comedic moments in the manga, but the more humorous part of it is Takahashi's reactions to what the boys say.
Overall, I would say that if you are looking for something relaxed and funny, you will probably enjoy this.