This was good! But it doesn't get really intense until the last 20 pages, and she kills Gangsta the dog, which is more disturbing than what she does to Aoyama. There's also a lot of heavy-handed foreshadowing that undermines potentially subtle unfolding horror. I also didn't love the info dump about Asami in the end. I think it would have been more creepy and effective if there was no bludgeoning foreshadowing and the info dump about her motives. Surely there's a way it could have been incorporated more smoothly. 

In terms of the horror, I'm going to guess the movie is worse because the book is fairly tame (to me). Aoyama is a believable middle-aged dude--flawed but not totally dislikable. He's a guy in the late 1990s. Enough said. Asami is just plain Not Right, and her creepiness factor ramps up as the book progresses. 

This is a fast read in addition to being on the short side. I enjoyed it, but I didn't quite love it.