The title's a lie. This series certainly has a ton of sexual content, some of it disturbing, but the film's not about invisible perverts. Instead, it's about people (here women) who turn invisible because they want to kill the objects of their vengeance.

Furthermore, the film has surprisingly little invisibility. The opening scene has an invisible person hunting a woman in her apartment, after which our bottle-blonde Satan (as in the title!) does another of his deals with a would-be killer. (He wears a white monk's habit.) That's just to keep the audience happy, though. We won't see any more of that for a while. It's a good half-hour before we see Satan again, then longer still until one of his clients uses his "devil's perfume". (It's not true invisibility, though. The perfume does things to human brains and stops people from perceiving you, but this won't affect security cameras and is also unreliable. Its effect weakens, for instance.)

Instead, we're watching Himari (played by Ema Futaba) try to become an actress. She's a nice girl who trusts a bad man (played by Yuya Ishikawa) and gets tricked into becoming a prostitute.

"Does everyone get naked at auditions?"

This is horrible and it breaks her. She'll obediently perform fellatio and so on, but after only 20 minutes she's already trying to kill Yuya Ishikawa with a cutter. She turns kind of psycho. She uses that cutter on a man she doesn't know who'd been trying to help her. Bloody hell.

Ten minutes later, she's entering the zombie-like state we saw in the first film. After sex, her customer complains that she was dry and rough down there. She responds by biting him at the most cringe-inducing time to bite a man. Afterwards, there's blood on her mouth. She's becoming a serial killer, or at least a serial injurer/mutilator. The whole thing's ghastly. She was nice! We'd wanted her to be happy. Instead, her latest evil pimp decides that she's so broken that she's useless.

They sell her to an actual serial killer, but that doesn't go as expected either.

After this distressing narrative, eventually we meet Himari's sister Merei. She's negotiating with Satan. There will be stabbing, a body count and at least one big surprise for me. I hadn't expected SPOILER at all. Himari's last scene in the film actually has her smiling and laughing, but what she's enjoying is basically a snuff film being enacted on her instructions.

Also, that "woman being hunted down in her apartment" opening scene was a flashforward. We'll see it again, with context and continuation.

There's heavy crossover with the first film. Lots of actors appear in both, while this film repeats a scene from the original for a surprise continuation (with further death). We even meet that yakuza played by Hirokio Andou who appears in multiple Daisuke Yamanouchi films and has facial scars like Kakihara from Ichi the Killer. His name's Hiraiwa and he has a wife (Hatsuki). Twice, she phones him and he says, "I'm in the middle of work" (e.g. putting a sack on a man's head and beating him to death with a crowbar). Also, during her second phone call, she must be able to hear the screams.

This film is horrific. Strong, yes, but a million miles away from anything you'd call "happy". Incidentally, Daisuke Yamanouchi's made a 3rd and 4th film in this series, both released in 2024, but I haven't yet found copies. Obviously, I'll watch them when I do.