I have noticed that tendency in Miyazaki's films, with the (IMO) exception of Nausica.
How is the book explicit-content-wise? Both SC and Cryptonomicon had a couple places where he describes sexual encounters in relatively graphic detail. While I'm not particularly offended by them, neither do I think they add anything to the book.
There is one scene that depicts a vaguely sexual ritual of a certain tribe-- it's somewhat graphic, but not in a sensual way so much as a scientific way. There's a similar scene later in the book that is quite a bit more explicitly sexual.
Those are the only ones that come to mind, though.