When Newtonian physiques meet Japanese gravity

Eleven great glass dishes radiate out in a circle across the stage, each cradling a shimmering pool of water. The floor beneath is a bed of spreading sand. Bathed in a low yellowish light, a cluster of pale grey "boulder" people nestle down in this sand. Almost imperceptibly they stir. They attempt to sit, but don't seem to have the strength, not sure perhaps if the time really has come to awake.

Eleven great glass dishes radiate out in a circle across the stage, each cradling a shimmering pool of water. The floor beneath is a bed of spreading sand. Bathed in a low yellowish light, a cluster of pale grey "boulder" people nestle down in this sand. Almost imperceptibly they stir. They attempt to sit, but don't seem to have the strength, not sure perhaps if the time really has come to awake.

This eerie, primordial landscape is the world of Sankai Juku, Japan's leading Butoh company, who bring their stylish mirage to Sadler's Wells next week.

The piece is called Hibiki, which translates as "a distant resonance". Its every movement is considered, controlled, intense. The figures learn to rise, peer into the water, unbow their heads and scan the sky. They move tentatively, with a low centre of gravity, feet connected firmly with the ground. Swaying in sinuous unison, their long white skirts swish while a red egg hangs like a pendulous plumb-line from each laced corset as the dancers' arms reach out to feel the air, like sleepwalkers.

In a moment of elated elevation, the androgynes suddenly spring skywards, before sinking back down to the sand, and reassuming their position of foetal sleep. The water drips on, and a faint tracery of footprints now patterns the sand, like bird-tracks on an early-morning sea-shore.

"It's circular. It circulates. Life is a continuous river," nods Sankai Juku's formidable founder, Ushio Amagatsu, after the performance.

Continuity matters very much to Amagatsu. What does he require from his dancers? "Concentration and continuity". How has his work developed? "There is little variation in style. I want continuity between one piece and the next." How different is Sankai Juku from the traditional Butoh "dance of darkness" style developed in the 1950s by Tatsumi Hijikata and Kazuo Ono? "I am the second generation. But it is a continuity."

Amagatsu founded Sankai Juku 25 years ago, and remains the guiding force at the centre of the company. After first studying modern dance, European-style in the 1960s, Amagatsu met Hijikata and went on to develop his own Butoh style. Sankai Juku is somewhat gentler and less bleak than the new dance-form which Hijikata created in the post-Hiroshima period, to try to show a way of accepting suffering and learning to live with fear. "We are broken from birth. We are only corpses standing in the shadow of life," Hijikata had declared. "There is no way that one can understand the nature of light if one never observes deeply the darkness."

"Butoh asks always what and why," whispers Amagatsu. "I continue to ask those questions. There are no answers."

Choreographer, dancer, designer and director, Amagatsu still devises every element of every production (apart from the music) from the conception of each movement, to the creation of the visually stunning sets, costumes and lighting. Now aged 51, he still takes the central performing role.

He has rinsed, now, the white paint from his body and the little lightning flashes of scarlet from his cheeks. An elfin face balances on top of a black polo-neck jumper, a Marlboro cigarette is always in his hand.

"Perspective is important," he says. "About a month after conception, the body evolves in the space of a week from fish to amphibian, reptile to mammal, as if replaying the whole of evolutionary history that took place over dozens of millions of years. We hold the memory of that primitive life within us."

"At least once a day, every human lies down," the dancer-philosopher continues. "Day after day, as day passes into night, in a movement that runs from east to west, every human on the planet lies down, one after the other, like dominoes toppling each other, until the action is repeated in reverse, everyone rising one at a time, in a continuous motion. Every day from birth, the same action is repeated, this gesture of rebirth."

"Get up, stand up, move – our every movement is a dialogue with gravity," he says. "Normally in dance the shape and form of the jump is the most important thing. For me it is the opposite. What interests me most is the shape when the dancer meets the floor again. Jump but return. Always the return. My basic idea about dance comes from Isaac Newton."

'Hibiki': Sadler's Wells, N1 (020 7863 8000), Tuesday to Saturday