As another commenter has said, the plot is indeed deep, sweet and in a way - very beautiful. The evolution of the plot does not seem rushed, but isn't excruciatingly slow as well.
Perhaps it's due to my undying love for the byronic heroes, but for me probably the best part of the story are the main characters who are flawed and imperfect from the beginning up until and including the very end in a way that's coherent with their storyline. No sudden and unexplained end of long-term depression and damaged mental state, just a little improvement.
Usually even the male characters with the worst, well, character, tend to have everything - money, women, no troubles communicating with the world, etc. In this story the mangaka has broken this "rule". The girl is probably a bit too overpowered when it goes to the charisma, but not to the level of other shoujo-manga characters. In this case I can actually understand people liking the sweet and innocent girl.
The situations are not overly romanticized or sexualized, hence the "slice of life" in the genre, though quite a generous amount of humor is added, probably just enough to retain the readers from climbing on the nearest roof and jumping off. Though I usually dislike the classical endings, here it is done with style and actually makes sense, seeing the nineteen of twenty chapters leading up unto it.
The only thing that bothered me a little at the beginning was the art as it looked somewhat, well, unfinished, but in the end a little bit of sketchiness seems to be very adhering to the characters and scenes.
In short - read it if you can take some amount of realism and the fact that the storyline might not be particularly happy or the characters perfect does not make you run away screaming.