Confessions, Tetsuya Nakashima, 106 mins (15)<br/>Justin Bieber: Never Say Never, Jon Chu, 105 mins (U)

A Japanese thriller fails to live up to its promising start, and the jury's still out on the Canadian singer

This year, the Japanese put forward Confessions as their contender for the Best Foreign Film Oscar, but they can't have been too surprised when it didn't make the shortlist. A cold, calculating drama revolving around a child-on-child murder ... it's hardly The King's Speech.

The film opens in a grey school classroom. Ignoring the chatter of the 13-year-olds in her charge, a teacher (Yuko Moriguchi) calmly informs them that her own young daughter is dead. She then explains that two of the pupils in the class were responsible. And finally she tells them what she's going to do about it. There's some throbbing ambient guitar and some disorientating slow-motion to keep us on edge, but in essence this attention-grabbing opening is a one-woman play that's as gripping as a heist movie.

It adds twist after twist until it's clear that every casual remark we heard in the first few minutes was placed there with a precise purpose, and it builds into a damning commentary on celebrity and the media. It's a perfect half-hour, during which you barely draw breath, so when the teacher concludes with the words, "That's the end", you wonder where on earth the film can go next.

The answer, I'm afraid, is "nowhere in particular". There are further "confessions" which fill in events before and after the teacher's testimonial, as seen by various pupils and a colleague. But the new ironies and revelations come to sound like ever fainter echoes of that initial monologue. By the end, it feels as if the first half-hour of Confessions is a film in its own right, and all that follows is a series of sequels and prequels. The slow-motion and non-stop music is mesmeric for a while, but it becomes a pain. In other words, Confessions wouldn't merit an Oscar nomination even if the Academy had acquired a sudden taste for bleakness. But if it had ended after the teacher's confession, it might well have made Best Short Film.

Confessions could be seen as a fearmongering indictment of the effects of the internet on impressionable youngsters, but it isn't half as scary as Justin Bieber: Never Say Never, a documentary-cum-concert video featuring the Canadian 16-year-old who was propelled to superstardom by some YouTube clips of his singing.

It's a slick product, adroitly designed to assure Bieber's schoolgirl fans – he has no other kind – that he's both an ordinary boy-next-door and a divinely talented superhuman. Accompanying parents will be relieved that the pacy editing reduces most of his songs to snippets, and there are enough sceptical asides to suggest that the film-makers have a sense of perspective, even if Bieber doesn't: one montage compares his YouTube clips with those of pandas sneezing and babies giggling. I'd throw in a comparison with last year's Fred: The Movie, also about a skinny, mop-topped teen who founed fame via the web. Never Say Never is far less irritating, mind you, but still has its repulsive aspects. Bieber's air of entitlement in the face of screaming fans is nauseating, while his vaunted dues-paying amounts to the same tour of shopping malls and local radio stations that pop wannabes always make. The real story is the unprecedented role of Twitter and YouTube in fast-forwarding Bieber. Who needs X Factor when you've got a laptop and a webcam? Never Say Never isn't in the same league as The Social Network or even Catfish, but in documenting the power of the internet, it does have something to say.

Next Week:

Nicholas Barber risks an obscenity trial by reviewing Howl, starring James Franco as Allen Ginsberg

Also Showing: 20/02/2011

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