Dance: Beautiful? Yes. Thrilling? Noh

Sankai Juku Sadler's Wells, EC1 Gilles Jobin ICA, SW1

Ushio Amagatsu is not a man in a hurry. Long minutes elapse before you even clock the fact that he is not an alabaster statue, mounted high on a plinth on the far wall of the stage. Even then it's only the merest stirring of a wrist, and then a slow unfurling of a forearm, followed by a gradual thawing of the smooth white ribs and neck that tell you he's a thing of living flesh. If the word "quick" were still in use as the opposite of "dead", you'd be tempted to assign him to the latter.

Amagatsu is the most celebrated exponent of ankoku butoh (or "dance of total darkness"), Japan's chief contribution to 20th-century dance which grew out of anti-American protest in the late 1950s. Imprinted with the crabbed, anguished forms of the Hiroshima victims and harking back to the pared-down symbolism of Noh theatre, the result was a kind of body sculpture in which the performers attempted to distil extreme states of being: terror, exhaustion, pain, birth, death. In the words of its founder, butoh is "a corpse which stands upright with the energy of despair". It's no holiday.

But to judge by the showing of Amagatsu's group Sankai Juku, on its first visit to London in seven years, much of the deliberate rawness has gone from butoh since those early days. In 1959, there was uproar in Japan when someone simulated the rape of a live chicken on stage then strangled it to death between his thighs. In 1999, these smart second generationers are the toast of the Parisian fashion crowd and their bald heads and white garb - though still ostensibly based on the traditional swathes of sheeting - would look perfectly at home on a catwalk. In their current piece, Shijima ("The Darkness Calms Down in Space"), even crucifixion is presented as an elegant and modish way to go.

But if you can swallow the idea that style rules OK and don't study the content too closely, then what you've got is something very beautiful indeed. The stage floor is covered with golden sand, the walls with a spectacular plaster bas-relief of naked bodies, the muscles making shadowy indents on the surface, the hollows of flesh forming mysterious mounds and curves. Bathed artfully in different kinds of lighting, this monumental catacomb provides constant interest for the full 90 minutes of the piece.

Which is more than can be said of Amagatsu and his five male clones, whose shaven heads and whitened skin have the effect of effacing not only their gender and racial identity, but to some degree their humanity as well. These wraiths from outer space present immaculately synchronised formations, but with such excruciating slowness that you could close your eyes for five minutes and barely miss a thing.

There are memorable effects, such as when the dancers appear as water- lilies in huge disc-like skirts, their hands making intricate, tendrilled movements to the far-off tinkling of bells; or as warriors, all hunch-shouldered machismo, until suddenly deflated by a series of dull thuds in the score - an unmistakable reference to bombs. In the final scene, all five bodies are hauled up by the arms on wires and left endlessly suspended as if on invisible crosses in mid- air - an impressive, but also offensive coup de theatre.

Yet for all these remarkable stage pictures, the absence of emotion made it hard to respond in anything but an abstract way. Shijima left me cold. And its quasi-religious symbolism struck me as symptomatic of the current fad for espousing any and every spiritual tradition, just as long as it's weird. I read somewhere that "butoh can mean everything, or nothing". In this case, I'd plump for the nothing.

There was much more honest flesh on view at the ICA, courtesy of the London Mime Festival, in a thought-provoking show with the title A+B=X. This may have had something to do with the fact that we saw one naked man (Gilles Jobin) and two naked women (the gloriously named Nuria De Ulibarri and Ana Pons Carrera) but in the end ceased to notice the difference.

Looming out of the dark, what looked like three bare backs were projected with an amusing film of three gurning male faces stricken with photo-booth embarrassment. Only when real live hands emerged to scratch the celluloid men's chins did you realise that the film was being screened on upturned bare bottoms. And unembarrassed bottoms at that.

The show went on in this witty and provocative vein to explore the nude in art, making many an art-college reference along the way - one dance featured the famous glass coffee-table nude, another (using clever chiaroscuro lighting) mingled dancers' limbs to look like Matta's disembodied organic forms. One of the women balanced spread-eagled on Jobin's heels to resemble Michelangelo's ideal male. A+B equalled a very interesting evening indeed.