Okamoto, a prisoner, finds out that his sister was raped and murdered by American soldiers while he's in prison. He finds a way to escape from the prison and decides to seek revenge on the people who did it.
"Zoom In: Sex Apartments" made it clear that some of the Nikkatsu flicks had things to offer outside of stupid erotica. Like "Zoom In", "Sex Hunter: Wet Target" is never entirely clear from the erotic stuff, but it seems quite obvious that it had a script that craved for much more attention than the producers would end wanting to give it.
While in prison, a man hears about the death of his sister. She had been murdered by a violent gang of men from the U.S. military. As any loving brother would, he escapes from prison and decides to find the bastards who did it. This revenge saga slowly, between overlong sex scenes, dig deeper and deeper and eventually reveals something more than just a simple accidental murder.
If it sounds interesting it's because it really had the potential to be that. These Nikkatsu films are just around 60 min long so you can imagine the toll that the script has to pay when a number of sex scenes have to be added, and they often go on for quite some time. The surprise here is not that there's mostly sex in the movie, but that the other stuff was as interesting as it was. Obviously, that's the least you'd expect when the script was penned by Atsushi Yamatoya who also wrote "Branded to Kill" and the much later "Dogra Magra" (let's ignore the lesser movies of his, for the sake of highlighting my point). I wonder what the movie would've been had it not been produced as erotica, but as a serious crime/revenge flick.
Enough of the "what if's", let's focus on what it is then. I think it's an above-average Nikkatsu erotica because it has a story to offer. The sex scenes feel slightly more serious than in some of their other productions, which might be because of the general tone of the movie, but I still think they fail to arouse. Generally, there's not much that differs between all their different movies when it comes down to the sex, so if you've seen a few then you know what I'm talking about.
"Sex Hunter: Wet Target" oozes of something really interesting, but walks down the same path as other Nikkatsu movies. It's one of the titles I'd highly suggest if you're curious as there are some good parts in it as well. Hell, there are a few shots that are downright brutal! But it all boils down to how many subpar sex scenes you can endure between all of the story.