@Freestyle: I TOTALLY get where you're coming from and let me start off by saying I'm not trying to change your mind about reading it/not reading it. I'm just giving a viewpoint.
The MC not being anything special is sort of the point. She's been with multiple guys, yeah, but he's a genuine person with his morals on straight, unlike the other guys she's been with who made it clear they were after her body, not so much her heart. So while he's nothing special to US, he's a complete 180 to the other guys, making him something special to HER.
If you read on, you'll find she does have a personality, she's just expressionless to the point of being cold. A "kuudere" is what her type is called (Ever read Suzumiya Haruhi? Another example is Yuki Nagato. If you like girls with personality, they don't get moreso than them!). The charm is when they break their emotionless face and smile or get upset or whatever else. Her sleeping around is not so much a core feature as it is the plot of the story: she's judged for it and only the MC seems to be able to look past it (not ignore it or think about it, just able to move past it and not think with his dick like the other guys in school). She knows she's judged for it and is finally learning how to let that go and learn to love, not make love, making this a pretty fluffy story, despite the background.
This is just my perception of it, though, so take it for what it's worth.