It's approximately a sequel to Suicide Club (2001). I've even heard that they'll eventually become a trilogy, but I don't believe Shion Sono's started on the third film yet. However that said, it's so different from its predecessor that they're not even in the same genre.

Suicide Club was warped, appalling and occasionally hilarious, defying easy categorisation in a similar way to something like Battle Royale. It was addressing contemporary Japanese social concerns, specifically existentialist despair and the suicide of its young people, but it was doing so through the medium of gore comedy and people doing gross things to themselves. It's not a horror film, but you'd need a high horror tolerance to be able to sit through it.

Noriko's Dinner Table, on the other hand, is a drama set in the same fictional universe. It's also not far off three hours long. Noriko is a pretty schoolgirl in geeky spectacles who's unhappy with her life and whose father doesn't understand her and... no, wait. It's not what it sounds like. Forget any preconceptions about the Japanese schoolgirl genre. There's heavy use of first-person narration and hand-held cameras, although these are merely devices to get us as close to Noriko as possible and this isn't another "filmed by the protagonists" movie like The Blair Witch Project or Cloverfield. Furthermore Noriko isn't wibbling on about boys, make-up, pop bands and so on. On the contrary, she's a serious-minded girl who's intelligent and observant when it comes to her family and her hometown. Her father doesn't talk to her, but to a daughter-shaped hole in the air. Her mother barely exists. Her observation that no one understands her isn't just the usual adolescent whining, but a perfectly level-headed assessment of the situation. Before long she's found herself a group of online friends and is planning to meet up with them in Tokyo.

This is where we remember that we're watching a sequel to Suicide Club and start getting scared.

Well, I say "sequel". It's more of an "enveloping", covering a two-year period somewhere inside which fall the events of Suicide Club. It's providing context rather than answers. You certainly don't need to have seen the earlier film to follow this one, although you'll need to be prepared for this film to be treating the suicide craze as background that needs exploring rather than explaining.

Anyway, that first hour is charming. Noriko's likeable and earnest, her town looks lovely and I'd have been happy to watch her doing nothing all day. The story's hardly pushing forward, but I didn't care. Unusually for Shion Sono it doesn't have many laughs, but I was amused by the cute and silly cameo performance of Yoko Mitsuya as Mikan. This could almost be the same adorable small town that we saw in Exte. This is crucial for the film, because if Sono's going to explore the psychology journeys that might end in suicide, he's not going to be saying very much if he starts out with urban despair and desolation. "Having a shitty life sucks" isn't exactly the world's most profound statement. Here though he's showing how nice girls from a good home can still end up running away to the city and getting into all kinds of trouble.

In Tokyo, things get darker. Noriko falls in with a character played by Tsugumi, who you might remember as the queen bitch of all bitches in Exte. Here she's one of Noriko's online friends and someone who helps her find a new life in Tokyo, but let's just say that her psychology is not straightforward. At first she's sweet and friendly and it doesn't matter at all that Tsugumi has the face of a predator. Then she shows her harder side. Then she... wow. Tsugumi's a fascinating actress, but she scares the living daylights out of me.

This film is about many things, but the main thing I took away from it was communication. How many of us tell everything to their families? You can have lived with someone every day of your life and yet know nothing about them, whereas sometimes you'll find yourself baring your soul to complete strangers. It's called the internet. Shion Sono finds some surprising visual representations of online communication, by the way, such as silhouettes standing in front of windows or else cacti and parrots. More importantly he's also saying some vicious things about the modern generation gap, with the comparison between Noriko's various dinner tables being a lacerating indictment of the lies, wilful ignorance and self-deception that are better known as family life. Noriko's father Tetsuzo is a good man who's trying to do the right thing for his family, but he's also so rigid in his thinking that trying to get inside his daughters' heads pretty much breaks his brain.

This is a long film and it feels it. The first hour flew by, but it becomes more of a slog as the characters' lives get colder and more disturbing. This is not a jolly movie. It's proper drama that's exploring its themes at length, which means that it's going to bore the arse off any fourteen-year-olds in the audience. One part I liked was the bit where we learned about a character's suicide in passing, whereupon the film doubled back and made us realise that even we'd never really thought about this person before.

I like the soundtrack, though. There's lots of gentle guitar music which makes everything seem warmer and more reassuring. Warning: it's not present in all scenes.

Tsugumi's character's line of business is freaky enough that it's probably going to push some people out of the movie completely, although these will be people who've never been to Japan. Be warned also that Sono pushes his theme of broken interpersonal relationships a long, long way. I was chilled when we saw two close relatives doing the equivalent of calling each other Mr and Mrs Bennet, except that this is the 21st century. Then of course you've got the fact that this film is made by someone who's (a) Japanese, and (b) called Shion Sono, so it seems a safe bet that you're going to be presented with something insane and appalling. Let's just say that this film is divided into chapters, of which the last one is called "The Knife In My Pocket".

Quick note about the cast. The main draw for me is Tsugumi, but everyone's good. The huge and unforgiving role of Noriko is taken by Kazue Fukiishi, whose naturalism is flawless even with the camera practically shoved up her nose throughout. She was also in Takashi Miike's Chakushin ari (2003). Then there's Ken Mitsuishi as her father, who you can also see in Audition, Exte (like Tsugumi) and even Terence Malik's The Thin Red Line.

This isn't a film you're meant to enjoy, but you also won't forget it in a hurry. One thing I'm grateful for is the conclusion. You couldn't pretend that it's doing a Disney ending, but fortunately it's also not as soul-destroyingly depressing as I'd previously been fearing. Characters make the correct decisions, I think, or at least ones that are understandable in the context of what the film's telling us. By that point, the superficially happy ending would have been a betrayal. On balance, I think I liked this film, but I'm not sure that Shion Sono's a well man.