I tried to read this. I really did, but the thing is, it seemed to have all the important incidences, where the Heroine learns something or makes an important choice, but are lacking the actions leading up to those choices. The characters are too self centered, or one sided, with plot holes galore.
Early on, the sister shows no disregard for her sister's things and the only explanation for it is that she's cute and pretty. Her classmates are cruel in a way that is worse than petty, and in reaction to some of their actions--which are worth a call to the police--she forgives them in exchange for them telling everyone else to stop being mean to her. In scenes like this, the person is usually never forgiven so easily, especially for that type of action, and even if the protagonist did end up on top, she would still be scarred and frightened due to that situation happening. If you've read enough to the part with the foot race, then you know what I mean.
When the characters' back stories are explained, it is still lacking as they were put together sloppily. The actions of Tsubaki's old girlfriend are not plausible unless she had some sort of abuse story, but the manga didn't even address that.
Basically, this manga, while pretty to look at, doesn't hold much for the plot. But if you can stand such undeveloped characters, sad plot, and irritation that this manga has, then go for it.