The plot... ehh. I've seen it before, and I wasn't necessarily moved. It had too much unresolved drama piling and piling, and that was not only irritating, but got in the way of the characters.
In the way of character development... only the two main characters had any "development," and that development was of the shoujo kind. From the beginning, the story seemed kind of superficial and fictional, which for the serious topics it covered, could and should have been a bad thing.
However, it wasn't a bad read. I don't regret the time I spent reading it, and as a manga, I think it depicted what the author wanted to depict. As for realism, there were some elements of it. It wasn't entirely fabricated, and unlike previous reviewers, I felt that the main girl's personality was fine. Not to be pointing fingers, but I feel that anyone that has a set way of how such a girl (i.e. those that have gone through teen pregnancy/were raped) should act hasn't experienced life any more than a "teenager." I will hold back my biting comments toward a previous reviewer's mention of a k-drama representation because this is supposed to be an objective (ish) review. Anyway, the way the flashbacks dealt with how she developed were well-placed, and added to the bulk of the story.
The emotional strain on the reader I felt wasn't huge. In fact, the characters felt so distant to me, and it had nothing to do with whether they were "relatable" because of similar characteristics. It might just be this author's style. Or the fact that, with issues such as these, it's just difficult to portray a person with such a past in a manner that has the reader absorbed. You either like the plot, or you don't.
One thing that wasn't addressed that really should have been was the issue of pity. I appreciated the subtlety of its development, but the way the author just abruptly ended the light sense of issue put me off. If that had been more masterfully developed, this manga would have been above-par for its genre.
My end recommendation? If you like the summary, read it. It's a pretty accurate representation of the story. The male lead is quite like-able in the sense of the word, and if you can manage to see past all the random plot elements of drama, I don't think you'll regret reading it.