South of the Border, West of the Sun

I recently reread the Murakami novel South of the Border, West of the Sun, and I have three observations to make:

1. Part of Murakami's signature style seems to be having male narrators who are utterly horrible human beings and come to realise this because of the women in their lives. Hajime in this book is a serial adulterer (although he's painted more sympathetically, and more convincingly sympathetically,  than I even thought was possible for a character of this type), K in Sputnik Sweetheart was a homophobic sleazy libertine, and Tohru in Norwegian Wood was an incredibly flaky and pretentious hippie. (To be fair, in Sputnik Sweetheart Myu was a pretty unpleasant person in the past too, and it took a doppelganger and several years of living as a ghost to make her more sympathetic.) I'm not sure what I think of this trend. I hear that Kafka on the Shore, Hard-Boiled Wonderland and the End of the World, After Dark, and The Wind-Up Bird Chronicle are very different, though, because they don't focus on sex and romance.
2. My theory? Shimamoto is either a revenant or a secret agent. It speaks volumes to Murakami's writing that both of these explanations make equal amounts of sense.
3. Does anybody know if hysteria siberiana is actually a real condition? It reminds me a little of susto.