That's great news! Red Classroom is the second in the series and Red Porno is the fourth with Nami coming in between. So the order is:
1. High School Co-Ed - which is sort of a juvenile delinquent film gone bad. Quite entertaining though, and there are some brilliantly framed shots, particularly one in a narrow alleyway early on where you have foreground, mid-ground and far background characters all interacting together, which may be the best shot of the entire series! Unfortunately that film was only available in the US Artsmagic DVD set in a cut down to 1.85:1 ratio from its original 2.35:1 ratio aside from its opening and ending credits, so that may be a reason for why it is being skipped over, even in the Japanese releases. It would be excellent to see this in its original aspect ratio however! I wrote this one up on Letterboxd on a re-view a few years ago:
colinr0380's Letterboxd review wrote:A difficult film, as a bunch of biker gang louts (who we get introduced to beating up a guy in his obnixous canary yellow sports car then gang raping his girlfriend) ends up tearing itself apart over masculine displays of dominance to each other. This takes the form of one of the gang, the 'good' one who cares for his sister, being taunted into raping another girl (called Nami, the name of the main female character in all the Angel Guts series) that the gang have their eyes on in order to prove his loyalty.
This cannot really be defended in terms of its portrayal of women as anything more than objects to be used and discarded, and the focus here is much more on the men in the biker gang than anyone they assault. Yet there is a fascinating blue collar portrait of the industrial areas of Japan that rarely gets seen (outside of Shohei Imamura's films), some fascinating location shooting on busy streets and roads, and some really stunning photography throughout this film. Not just the eye-catching sequences of hyper contrasty black and white nightmares or the eventual rape of Nami taking place in a torrential rainstorm on the tracks between two train boxcars, but also in the way that the film shows beautifully layered action in general scenes. Particularly the beautifully composed scene in the alleyway introducing us to Nami in which an assault on her by one of the gang is prevented, which has action in the very foreground but also a long view down the alley to characters standing halfway down and observing the action, and the exit at the very far end that Nami has to run down to leave the scene. Or the beautiful use of geography in the scene in with the camera is mounted on the front of a motorcycle as it travels around the backstreets and back to the main road, encircling the waiting Nami.
2. Red Classroom - this one is really good as a dark and fatalistic drama about the fallout of rape. Our main character Muraki is introduced watching an illicit stag film with a group of other men (the exact same kind of scene that occurs in Imamura's The Pornographers!) and gets enamoured by the actress in the scene of a schoolgirl getting gang raped in a classroom. He tracks the woman down, destroying his life in the process, and eventually finds out that she was not acting and it occurred for real. Nami is so damaged in this one, and Muraki's attempts to drag her out of the cycle of being used by becoming her lover ends with a beautifully tragic final scene of missed connections taking place in the pouring rain (pouring rain is a motif in all of these films)
3. Nami - this is rightly seen as the classic (and most horror-themed) of the series, as Nami here is a mercenary reporter for a women's magazine who is running a series of articles about rape victims, which involves her paparazzi-style tracking down the victims, forcing their stories out of them and subjecting them to a barrage of up close unconsensual photoshoots whilst the women beg them to stop (which is another motif of the series). She gets involved in a kind of His Girl Friday-style fractious-romantic relationship with rival reporter-photographer Muraki. Sometimes Nami's approach works, as with one victim who has turned their assault into an elaborate stage-show stylised re-enactment and seems entirely fine with the extra publicity for the show that will come from Nami's article. But eventually Nami's callous 'pick up and drop' attitude to the victims of assault ends up returning to bite her, in the form of knife-wielding distraught women turning up at the newspaper offices and eventually the final section of the film where she ends up provoking the wrong person entirely:
by interviewing a nurse who has been provoked into insanity by her historical assault, and who ends up subjecting Nami to a thunderstorm-backed dildo attack and partial evisceration in the bowels of the hospital before she is saved at the last moment. That then is the catalyst for the final section of the film as Nami, having now experienced the brutality of assault firsthand rather than getting her rocks off to it vicariously, has a mental breakdown herself, and takes the film with her.
4. Red Porno - as the title suggests, this is the most explicit of the series (though not hardcore), in which the naive Nami decides to stand in for her suspiciously taken down with a cold friend at the photoshoot that she was meant to attend, and finds out a little too late that it is a bondage-themed nude photoshoot. The story is about the fallout of the photos being published in a magazine which suddenly attracts all sorts of men into Nami's life, from her boss wining and dining her before taking her to a Love Hotel, to the Muraki of this film who is a nerdy loner and potential stalker. This film plays out like a kind of a series of setpieces - an intercut sequence of Nami and Muraki masturbating in their separate houses under their Kotatsus (which Jasper Sharp helpfully explained and introduced the concept of under table-heaters with his commentary over this film - so sexy films
can be educational!); the assault on the metallic bars of a children's playground during a thunderstorm; and most eye-poppingly Muraki spying on the next door girl not doing her homework and instead improvising something entirely naughtier to do with a condom, an egg and a well-sharpened pencil!
5. Red Vertigo - the first film directed by Takashii Ishii, whose manga inspired the entire series, this is the 'noir'-style entry, with Nami a nurse at a local hospital who goes home to her photographer boyfriend early after an attempted assault by a patient, only to find him in the middle of a tryst with another woman. On running from the house she ends up getting knocked down by the Muraki of this film (played by Naoto Takenaka, years before he was the lead in Shall We Dance?), who himself is roaming around with his life in tatters due to being in debt to the yakuza. For some reason, Muraki takes Nami to a derelict location (which if you know your Japanese exploitation cinema is the same derelict US Army base that appears in the same year's slasher film Evil Dead Trap, itself written by Ishii) and they hole up there Night Porter-style to have an intense sexual relationship whilst awaiting the inevitable tragic ending.
So hopefully that gives a quick run down of the early Nikkatsu series of Angel Guts films. I think they are all interesting but of course should be approached with caution and with the foreknowledge that the assaults are mixed with sexploitation elements as well. But if you can manage that, they still generally treat the subject of sexual assault relatively seriously, and are mostly a series of very dark-toned tragic romances between deeply damaged people.