One of the weaker Wakamatsu films I've seen in a while. Not that it is so different from his other work, but somehow it lacks the urgency and the vigor that made his other films jump out. Without it, there's little more than a mix of unsexy erotica and endless monologues, few of them very interesting.
Though I'm not 100% certain, I think Sex Crimes is part of a series of films Wakamatsu made about deranged individuals that ended up becoming sex criminals. Either that or it's just a very recurring theme in his films. You pretty much get the same setup here, though with a slightly dull lead.
The performances didn't really appeal to me, the camera work felt a bit obligatory and there were some serious pacing issues. Maybe I'm getting a bit too used to these 60s Wakamatsu films, or maybe this is just a lesser film in his oeuvre. Time will tell I guess, as I still have a good 60 more to go. For now, I would say this is for completists only.