I liked Ju-on: The Beginning of the End. I thought that film was fine. I thought at the time that you could go on basically remaking the same Ju-on film forever and the format was simple and flexible enough that it would always work.
This film, on the other hand, fails. It's sort of approximately the same as all the others, but it's also pretty bad.
What it's missing, I think, is cause and effect. Audiences appreciate that. Cause and effect is what glues together a storyline in our brains. "The little girl went into the haunted house and got killed by a ghost." White-painted time-looped iterations of that are basically the Ju-on franchise. In this case, the cause is "she went into the haunted house". Our heroine probably didn't mean any harm and it's a bit excessive that it got her killed for it, but hey. At least we can join the dots. It's a horror film.
This film, on the other hand, isn't really interested in the haunted house. It's ditched the house that's been the cornerstone of the franchise and it barely even has Kayako. (She doesn't kill anyone!) Ergo, instead of cause and effect, it just has a whole bunch of spooky stuff happening without much obvious cause. It feels kinda random. It's not that interesting. The boy (Toshio) is important and there's some plot development involving him, but basically we've got people having dreams, hallucinations and spectral experiences in a sort of cinematic collage.
It opens like a sequel to the 2014 film, with a quick recap. Yui (Nozomi Sasaki) has a sister. Meanwhile it seems that Toshio (yes, him) has a cousin and an aunt, who take him in after all those tragic things happened to him. Well, more precisely to everyone around him. And their friends. And everyone who'd ever looked at him, quite possibly. If I lived in the Ju-on universe, I wouldn't be going anywhere near the other children in his old class at school. There's a little girl in the hospital opposite Toshio's aunt's house who has a habit of looking out of the window with her mobile phone camera. Unusually in this film, I actually got a bit scared by that little girl's scenes. With her, you see, the film establishes a classical cause-and-effect for the audience. It's nice and simple. Point your camera at a house with Toshio in. Look, there's Toshio. No, no, no, stop it, drop the camera now. Well, that wasn't a good idea.
The film has some ideas, though. It's exploring the nature of what Toshio is and the way in which the evil can seemingly infect new places and people. Toshio's aunt's house gradually becomes a second haunted house. I'm thinking particularly of that distinctive repeated shot of the upstairs hallway.
Oh, and in what sense is this "the final curse"? It's true neither in-story or in the real world, given 2016's Sadako vs. Kayako.
This isn't a dreadful film. It just doesn't really have much connecting tissue, i.e. "cause and effect". It's not completely shapeless, but it's kind of blobby and it basically feels like spooky things happening in a loosely connected way for 90 minutes. People talking to ghosts remains a pretty effective spooky idea. Some of these people are lovely, e.g. Nonoka Ono. This is the kind of storyline that no one would dream of turning into a film if it wasn't in the horror genre, in which people think it's permissible not to bother with a plot. In fairness, some horror films get away with that. This one doesn't, though.