In the Miso Soup by Ryū Murakami

It is just before New Year's. Frank, an overweight American tourist, has hired Kenji to take him on a guided tour of Tokyo's sleazy nightlife on three successive evenings. But Frank's behavior is so strange that Kenji begins to entertain a horrible suspicion: that his new client is in fact the serial killer currently terrorizing the city. It isn't until later, however, that Kenji learns exactly how much he has to fear and how irrevocably his encounter with this great white whale of an American will change his life.

《I didn't know if he was a murderer, but I knew he had a bottomless void inside him. And that void was what made him lie. I've been there. Compared to where Frank was at, it may have been like a Hello Kitty version, but I've been there.》

THIS. BOOK. IS. SO. DISTURBING.
Oh my- At some point I was going to throw up the hell out of me, seriously.
... But I have to say that from 80% on (I was reading the ebook version, of course) I was kinda bored, but obviously I wanted to know how it ended so I tried my best to finish it.
A final comment? I feel so paranoid right now. Just let me live in my bedroom and don't let me see the sunlight ever again, please.

I was on board for the first two thirds, but the book plays its hand way too early, and quickly goes from gritty and intriguing to aimless. The tension and threat evaporate and the story spends the third act petering out. I liked the writing and seedy atmosphere, but the violence and monologues didn't interest me as much as the suspense.

Not only is this book kind of hard to describe, it's really hard for me to say whether I liked it or not. I have no idea how to give it a start rating! I don't regret reading it at all, because it was strange and thought-provoking, but I certainly didn't enjoy it. Hmm.