That was unpleasant.
It's a Nikkatsu Roman Porno, which was what the studio focused on from 1971-1988. It's Japan's oldest major studio, but when television started biting chunks out of the Japanese film industry, it was either porn or bankruptcy. When home video came in the late eighties, mind you, bankruptcy came anyway.
What's more, the Roman Pornos were respected. They won awards. Today's film for instance helped Akira Suzuki win a Best Editing award from the Japanese Academy, even if that's merely as one of Suzuki's nine films in 1985, which also included Tampopo. Admittedly many of Nikkatsu's stars and directors had left rather than work under the new regime, but others stayed, including Shogoro Nishimura. Furthermore some of their films were popular with both male and female audiences, such as Ohara's Pink Tush Girl trilogy.
Other films of theirs sound disturbing, though. The scariest thing about Japan for me, for miles, is the idea you'll sometimes find that rape can be erotic. Some Roman Pornos were in an ultra-violent, misogynostic "Violent Pink" style. Rope Hell (1978), for instance, is about a female yakuza who's kidnapped and tortured by a rival gang, but comes to enjoy it. The eight-film Female Teacher series ended in 1983 after complaints from schools and parents, with Female Teacher: Twice Raped. Spot the link with today's film. I'd defend the Angel Guts films I've seen as having artistic worth, but I won't be making such claims here.
So, what happens in the film?
We begin with our heroine (Kayako) being sexually harassed in the classroom. She's a teacher and her students shout out filth as she walks past. On going back to collect something she'd forgotten, a group of boys are standing around a bucket with their trousers down, masturbating into it. On getting her shoes from the locker, she finds semen in them.
This brief introduction is the best bit of the movie. It's revolting, but you can't say it's not effective at what it's trying to do. Unfortunately it turns out that Kayako's hobby is having sex with any random man, including:
(a) a regular boyfriend (Toshiyuki Kitami) who's two-timing his other girlfriend and not even trying to hide the fact.
(b) an ex-boyfriend (Joji Nakata) even though he's now married to a friend of hers.
(c) an anonymous student in the school gym, probably visible to some other students who are using it for its intended purpose.
You might thus be assuming that the boys in the opening sequence were picking up on Kayako's reputation, but it sounds as if that's how they treat all their female teachers. No one in this film is sympathetic. They're either scum or throwing themselves at scum. Kitami thinks nothing of letting both of his girlfriends into his flat at once and doesn't even look at them while they're trying to discuss this. He makes no attempt at comforting them and if they start getting too emotional, he hits them. I think he might be a psychopath. He's also allergic to commitment, always wants to shag whatever woman's nearest to him and will openly say as much. It's like a personal philosophy for him, or possibly a mission.
It's not even as if he even seems to get any pleasure from this! He never even smiles.
Kitami's girlfriend seems nice enough, but she's badgering him to get married and won't shut up even when he shags other women practically in front of her. She's told her mother about the two of them, you see. "Marry me, marry me, marry me"... is this woman broken?
That's the more dysfunctional of the two triangles. The one involving Nakata is less abusive, but just as unpleasant because Kayako's seducing a married man who has a good marriage, a lovely wife and seems quite nice himself. Well, apart from the scene where the husband forcibly has sex with the wife when she's saying "no". We know a word for that, boys and girls. As with Kitami's two women, there's a scene where Nakata's two women are discussing what to do next with him, as if infidelity is on a par with forgetting to do the laundry.
That's bad, but I haven't reached the worst yet. Remember those students? One of them sends Kayako a letter saying that he'd like to rape her. This is foreshadowing. A nice thing happens for the first time in the movie at the 45-minute mark, when three students present Kayako with a huge basket of fruit, but "nice" then goes to hell and the scene turns into a gang rape. That's bad enough, but it's the movie's opinion of this that'll really turn your stomach. Afterwards, it's the boys who are crying. Kayako tells them to go home. (Wow, that really told them! She doesn't go to the police or any other authorities, of course.) Later she says that she can't even get angry at the boys for what they did, after which the movie's last scene involves the three rapists (I think) bowing to Kayako at school and her smiling contentedly as if at three new friends. The end. I think that's the "High School Teacher Maturing" of the title. Maturity is thus presumably the ability to have your life and personality improved by gang rape.
In fairness, other people have a learning experience too. Everyone in this film has a character arc. Kitami loses his beloved lifestyle, which he finds so distressing that he can't even get hard when being sucked off in a bar. (Guess who by?) I think I hated him the most in this scene, by the way. There's a fair amount of maturing going on all round and I can see that there's a novelistic level to this movie, underneath the softcore porn, but personally I can't get past the story's mindset.
In fairness, after being raped Kayako picks up a knife and looks at it. We're later told that she was considering suicide. Neither the actress nor the film made me believe this.
Do not watch this film. That shouldn't need saying, but I'll say it anyway. Burn it instead. By existing, it makes the world worse. The actresses here didn't go on to have careers worth speaking of, incidentally, but both men are still in the business today, albeit in Joji Nakata's case largely as a voice actor. He was Alucard in Hellsing
(both original and Ultimate). There's clearly a cultural difference going on with this film, but not all cultural differences are morally and ethically neutral.