Ikuo Fujitaka, manager of the Tao drummers, is explaining his philosophy of tough love over a glass of vodka and his 73rd cigarette of the day. "There used to be a strict spirit in Japan, but we now have a younger generation that doesn't have this spirit," he says. "I tell our trainees, 'You are slaves.' They can have no money. No telephone. No girlfriends. No boyfriends. No eating outside mealtimes. And definitely no drinking or smoking. For the trainees, it is like hell. In 10 years, 400 have dropped out.
"When I formed Tao in 1993, I intended to create the most disciplined company in the world," Fujitaka explains. After just a couple of hours at Tao's base in south-west Japan, I begin to wonder whether he has succeeded. Fujitaka's man-management makes Alex Ferguson look like a Relate counsellor. When one of the current drummers was a trainee, Fujitaka punched him for yawning. When another begged for a traineeship, he was told to shave his head to show his dedication. Hardship, the 45-year-old producer says, is good for the spirit.
To emphasise his point, he summons a graduate of the Tao boot camp. "What was it like being a Tao trainee?" he asks.
The drummer looks unsure how to respond in front of the boss. "I thought I would die within a year," he replies nervously. Fujitaka tips back his head and roars with laughter.
The alarming thing is that his approach seems to work. Already seen by more than a million people in Japan, Tao have taken the old saw about suffering for their art and honed it until each tooth is as sharp as a samurai sword. Their show at the Edinburgh Fringe is the company's British debut. High gloss, high energy, it confidently fills the slot occupied in previous years by percussion-dance spectaculars such as Tap Dogs, Stomp and Gumboots.
Perhaps it was just jet lag. Or perhaps it was the odd feeling that I'd come half-way round the world to end up somewhere that looked like the Scottish Highlands. Either way, the drummers' headquarters, on Kyushu, Japan's third-largest island, seemed peculiar from the start. It isn't the easiest place to get to. A two-hour flight to the city of Fukuoka is followed by a three-hour drive to the heart of the Asu national park. Known as Grandioso, the complex of buildings lies at the end of a treacherous mountain road. Nestling on the slope of a volcano, it would make the perfect hideaway for a Bond villain or an apocalyptic cult.
From the back lawn, the view is spectacular. Directly ahead, mountains fade into the distance. The isolation is idyllic but also a little unnerving. To Western eyes, Tao is a strange beast - as much a commune as a group of performers. Grandioso is where the drummers live when not touring. It is not enough simply to play the drums; the men and women of Tao must also cook, clean and do the laundry. When members of the public visit Grandioso, it doubles as a hotel; the performers wait on their guests and prepare their rooms between shows. It is just another small example of communal sacrifice for communal gain.
The company's fitness regime is brutal. A normal day starts with an hour of sit-ups and stretches, followed by a 5-10km run before breakfast. Only then, when most people would be longing to crawl back to their futons, does the real rehearsal start.
No training on my first morning at Grandioso, however. Instead, Tao will perform their famous sunrise show. By the time I stagger downstairs at 4.50am, they are in costume. A huge drum - the 200kg odaiko - has magically appeared on the lawn. Nobody yawns or grouches or does any of the other things you'd expect from a group of British performers roused from their pits, in the dark, after four hours' sleep.
The performance that follows is as strange and beautiful as a dream. Slow at first, a solemn thud drives out the dawn, answered by the ghostly call of bamboo flutes. As the sun clears the ridge of the hills, the tempo builds. Kishino and Taki pummel the odaiko, conjuring up a wall of noise. The strength needed to do that is immense, but when the photographer asks them to repeat their performance, they begin again as if the past 20 minutes has not happened.
After lunch, I take a nap. When I wake at 4pm, Tao are in the rehearsal room, dissecting the routines for their Edinburgh show, Tao - Beat of the Globe. At 10pm, the drummers break for supper; it is 18 hours since they started work. "Was today typical?" I ask Fujitaka at supper. No, he replies. "They got a rest for two hours in the middle, so it was an easy day."
Tao's unique strength is in taking traditional taiko drumming (not the most fashionable of art forms, even in Japan) and spectacularly adding some Western razzmatazz. Fujitaka's values may be distinctly old Japan, but there's something distinctly American about his outlook. One of the first things he did on forming the company was take it to Las Vegas to observe how that city's circus acts and magicians grab the audience and don't let go.
It's a lesson they haven't forgotten. Each routine of Tao's Edinburgh show is precisely choreographed and athletically executed; just as important, they perform with smiles on their faces. That cannot always be easy, you suspect. To succeed with Tao means renouncing things most people would take for granted - friends, family, relationships. It is, Fujitaka says, "a bit like a monastery". Members are allowed to have relationships once they've finished their training, but the constant touring (150 shows a year) and the remoteness of Grandioso do not make finding love easy. The only married member, Suito, has a six-month-old daughter in Fukuoka. "I see them about two or three times a month," he says. Would it help if they lived nearer Grandioso? "No; it's better they're far away. If my family lived here, I'd want to go back and see them all the time."
Even finding time to see friends can be difficult. What do they get in return for their dedication? "We don't just perform and entertain guests at Grandioso," says Arisa. "We're like family. Sometimes we fight, but we understand each other." That instinctive togetherness is evident on stage. Far harder for any outsider to grasp are the sacrifices and the mental endurance required. Even after you've experienced it close up, the way of Tao remains a mystery.
'Tao - Beat of the Globe', Assembly @ St George's West, 58 Shandwick Place, Edinburgh (0131-226 2428) to 30 August