Believe it or not, I actually do hate writing negative reviews -- especially when a book has been kindly provided to me expressly for the purpose of writing said review. 
 But I hate lying more than I hate negativity, so here we go.... 
 Usually I start out with a lovely, flowy description of the plot. However, I think I can sum that up in just one sentence. So, here we go.... 
 A girl cheats on her boyfriend with a pothead, ends up dead, everyone thinks it's suicide, she thinks it was murder, she stays around as some kind of ghost figure and tries to solve her alleged murder, then tries to make out (make up?) with her boyfriend too. 
 That's it. 
 So, why the one star? 
 Mostly, it's because I hate all of the characters. Every single one of them. 
 Let's start with the main character, Cassidy. She's just not the brightest bulb in the lamp, if you catch my drift. She's flighty, both in life and death, supposedly focusing on solving a murder, except she really spends more time daydreaming about kissing her boyfriend and trying to find a way to get him back even though she's dead. She's melodramatic, immature, and incredibly slow to catch on to every blatant hint thrown her way. She's so unlikeable that I, as a reader, had a hard time trying to even CARE who killed her (or why). 
 Now, we can move on to Ethan, the boyfriend. What is there to even say about him? NOTHING. He's unremarkable, boring, and unmemorable. I had to stop and look up his name before even writing about him. That's how little I could care about him. 
 Then there is Caleb, the pothead. Cassidy thinks she cheated on Ethan with Caleb, and in her pseudo-attempts at crime solving she really doesn't give a single positive quality about the guy that would make me even believe she'd cheat on her random boyfriend with this other random dude. She thinks Caleb may have killed her, although the only memorable flashback she even describes is the one where lover boy Caleb gave her a marijuana brownie before she "fell" off a bridge and died. 
 Drew, who is Ethan's best friend and Cassidy's best friend's boyfriend. Again, not one single positive quality is given to Drew, who is described mostly as a raging psychopath. Copy and paste that description for the other friend, whose name I already forgot. Those two were pretty much interchangeable to me throughout the story. 
 And then Cassidy's best friends? Apparently Cassidy has lousy taste, not only in men, but in friends as well. Aimee, at least, seems to care that her friend is dead. Besides the hints of ambivalence from Ethan, I'm pretty sure that nobody else in the book, including her friends and family, even CARE that Cassidy is dead. I'm not even sure that Cassidy's lingering ghost spirit cares that she is dead, beyond the fact that she can no longer kiss boys. And then the other alleged best friend? Madison? Can someone REALLY be completely oblivious to the fact that the person they see for hours every single day is a psychopathic stalker? Cassidy vaguely considers that her best friends may have played a role in her death -- although, again, she seems more concerned with daydreaming about kissing Ethan than about considering why she was surrounded by such a bunch of juvenile delinquents. 
 By the end, in all honesty, I couldn't care less why Cassidy died or who was involved. All of her friends were idiots, and nothing in the story seemed believeable enough to feel the least bit relatable or interesting. And, oh, the melodrama! I get that teenagers are full of raging hormones and confusion and despair, but murdering people over crushes or kisses or relationships that won't last beyond graduation? Good grief. 
 In trying to decide the intended audience for My Last Kiss, I can only think that this would be appealing to younger teenage girls with low expectations of men, friends, and literature. I really enjoyed the premise of the story, I think, but the horrific cast of characters killed it for me in the end.