** spoiler alert ** 
 A waste of a perfectly good title. A hedgehog is the last animal I'd think of as pretentious, and pretentious is just what this book is. 
 I found many things in this book very, very irritating, but the worst thing hands down are the two protagonists. They are smart, oh so smart. 
 Both of them spend most of their time complaining about how everyone else is a snob and just not as smart as they are. 
 Now, if Muriel Barbery had realized what hypocrites both of them are, this might have worked. But she's obviously very much in love with both her precious protagonists (who seem to function as an extension of herself) and doesn't see anything wrong with their behaviour. 
 There is Renee who is old, poor and ugly, but obviously smart. She's a concierge with a great knowledge of literature, art, beauty and Japanese films who spends most of her time trying to pretend that she's stupid, grumpy and useless (because that's what concierges are like) and then silently accuses everyone of snobism when they buy that. Yeah. 
 She does this because her sister had an affair with a rich guy and was dumped (and then died in childbirth). Because only poor people get dumped and only by rich people. 
 Then there's Paloma who is 12, rich, precocious but hiding her intelligence (why? I don't know) and planning to kill herself on her 13th birthday (and burn down her family's flat). Why? I don't know. Some non-specific "life is absurd" reason. She complains a lot about her family because 
 a) her sister likes loud music, Italy and has an apparently serious phobia of dirt which obviously makes her a terrible person, 
 b) her mother likes shopping and takes antidepressiva. How dare she! 
 c) her father...I don't know, he seemed perfectly nice to me. 
 She writes about her horrible family and other "profound thoughts". 
 This is all that happens. Two bitter, hypocritical Mary Sues complain about how everyone is a snob and also not as smart as they are, and go on irrelevant philosphical asides, because they are, you know, oh so smart. 
 Then someone moves into one of the flats and saves both of them by...being Japanese. That's all he does. Muriel Barbery has a slightly creepy Japan-fetish. 
 So everything goes well, until Renee dies. Well, shit. Unfortunately, having known her for...a few days, Paloma is so moved that she decides not kill herself. 
 I think what Muriel Barbery is trying to do is show how rare and precious smart, kind people are. Except her characters are pretentious snobs and absolute arseholes to anyone not belonging to their little smart people club, be it because they're rich or like shopping or misplace a comma. So yeah, that didn't quite work out. 
 There are some nice thoughts and details though, which is why I almost gave the book 2 stars rather than one. Paloma, irritating as she is, does write about some beautiful things, like the ecstasy she feels when listening to the school choir or her love of trees. 
 Also, there's a nice bit about finding a balance between the high brow and the low and inspired by that, I'll go watch tv and play Pokemon now. That's going to be more enjoyable than the book.