This movie (the first a series) is basically a low-budget, but actually pretty entertaining superhero spoof about a mild-mannered Japanese schoolteacher who teams up with his uncle to make money AND right the wrongs in society. The reason this will never get an American reboot though is the WAY in which he rights the wrongs in society--by handcuffing and raping evil women! The character is the serial rapist version of "Dexter" in that he only rapes women who "deserve it" ("righting wrongs through penetration"). But (as unbelievable as it is) people actually take "Dexter" much more seriously. The women in this movie are not just evil, they're cartoonish (if they had mustaches they'd be twirling them). Accusing a movie like this of "misogyny" is like accusing "Bugs Bunny/Roadrunner" cartoons of animal cruelty. Of course, this is pretty adult. The rape scenes are eroticized and the sexy, evil women (quite unrealistically, of course) end up enjoying the experience (which begs the question of exactly how much they're REALLY being "punished" here).
It is this latter aspect that would no doubt really wad the panties of the American "PC" crowd because it contradicts the bizarre idea that rapists, by and large, are poor confused souls who have been fooled by the media into thinking women "want" to be raped. But why give the REAL-LIFE scumbags that much credit? Rapists are mostly either sociopaths--who could care less about their victims (like most criminals)--or they are actual sexual sadists, who GET OFF on their victims suffering and would be very disappointed if their victims "enjoyed it". People have finally figured out the vast difference between consensual BDSM and sexual sadism. Well, the rape scenes in this movie are at heart consensual rape fantasy (which both women and non-rapist men at times enjoy) and simply are not going to have much appeal to genuine rapists.
It might be slightly more "offensive" that in his mild-mannered schoolteacher life his female students are all under-dressed, sex-obsessed "roritas" who give their hapless teacher a pair of their panties and tell him it's a handkerchief or tease him about becoming phone-sex operators (He gets flustered, but always remains very professional, and since they're mischievous rather than evil, they never encounter his alter ego). But maybe someday when people can separate harmless rape fantasies from actual rape, they'll also be able to separate harmless "schoolgirl fantasies" (these are actually pretty mature-looking "schoolgirls" and it wouldn't have been totally out-of-line for Rape Man to at least give them a good spanking)from actual pedophilia. In the meantime though the PC crowd should definitely avoid this, but it's a pretty fun movie for everyone else.