'For ready-to-wear I did the bottom of the sea in a very different way and after that I wanted to do the sky,' says Lagerfeld. 'So I used the integration of a plane for the showcase. It was inspired by the millions of different blues in the sky at different times of the day and year.'

Backstage, Lagerfeld watches the show on a screen with his right-hand woman, Amanda Harlech. She's often referred to as his collaborator and muse, but she prefers the term 'outside pair of eyes'. They look quite the pair - Lagerfeld with his velvet jacket, white ponytail, starched collar and gloves, and Oxford-educated Harlech, raven-haired, petite and serious looking.

'It's very touching in a way that he is always surprised by the beauty of the clothes,' says Harlech. 'We both thought this show was extraordinary. Sometimes when you repeat things it's not like that first performance, but it was so great to see it come alive again - the clothes have so much richness in them.'

This is the first time that Chanel's couture show has been reconstructed to full effect in Asia. And since couture shows do not tend to get such extensive media exposure as the ready-to-wear ones, Harlech wonders if they could be onto something.

The choice of city was no accident. At the press conference a day later, when Lagerfeld elaborates on his admiration of the Japanese people's response to last year's earthquake and tsunami, the room breaks out in an uncharacteristic burst of applause.

It is a touching moment, cracking fashion's hard veneer of platform wedges and overdressed interns. But then again this designer has never been one to follow the rules - think back to the 2004 collaboration with H&M that spawned the Swedish label's current string of high-profile collaborations. It was as if, after Lagerfeld went downmarket with H&M, it became acceptable for everyone else.

Born in 1938 in Hamburg, Lagerfeld's cosmopolitan upbringing and gift with languages made him naturally curious about other cultures. He has long admired the Japanese aesthetic, and his passion for Japanese architects is well documented.

'Japanese fashion has brought something new to the aesthetic of fashion as a whole,' he says. 'When Comme des Garcons first came to Europe, coming from the outside, they imposed a new, very interesting aesthetic that would have been considered ugly before.

'They imposed a new revolution in taste and ways of looking at fashion and beauty,' Lagerfeld adds.

Having been at the helm of Chanel since 1983, and since taken top positions at Italian houses Fendi and Hogan, as well as developing eponymous labels Karl Lagerfeld and Karl, to call this 73-year-old 'busy' would be a gross understatement. His creative exploits now include illustrations and photography.

Harlech first met Lagerfeld when she was working with John Galliano at Dior in a similar 'influencer' role. It was at one of Lagerfeld's infamous Paris fashion week parties of the 1980s held at his lavish rented residence at 51 Rue de l'Universite.

'There was Karl, the king,' says Harlech. 'Mischievous, wide-eyed, alert, challenging. So intriguing behind those dark glasses, and extremely generous.' They became fast friends and he came to her rescue when she had trouble renewing her Dior contract. The pair have worked together at Chanel ever since.

The cult of Karl has reached mythical proportions. Seas of people part and cameras come out when he walks past with his entourage. The man is not without his fair share of controversy - the most recent being the furore around calling singer Adele Adkins 'a little too fat'. Even in Tokyo, he lets a bitchy aside slip when he calls Tina Brown's Newsweek a 'shitty little paper' when asked about an article she printed that called him overrated.

People have generally forgiven these PR faux pas, partly because of his celebrity status - even film stars in his presence turn into nervous fans.

'Karl isn't somebody who obfuscates,' says Harlech, 'He has a very clear design message and often that's quite abstracted and pure. That's what makes him modern.

'He wants to know that it's hitting home. I'm a good sounding board, because on the rare occasions when I feel that something has been overworked, I will chime in with his instinct.'

When it comes to designing for a mind-boggling eight Chanel collections a year as well as the other labels and projects on the side, Lagerfeld is blessed with an acute sense of 'what's next?', which often comes in night visions and dreams.

'Sometimes in the early morning, before I really wake up, I have a vision and I sketch it. Some of the best ideas are invented like this, without me knowing how,' he says.

The idea of Chanel, adds Lagerfeld, relates to a specific quote by German 19th century writer and thinker Goethe. 'He once said 'make a better future by developing elements from the past': I think that's right for everything,' he says.

By this mantra, he's kept Chanel relevant for the past 29 years - no mean feat, as Harlech points out, citing the relentless turnaround of designers in fashion houses of late.

'Coco Chanel did that; she knew what women wanted next,' says Harlech. When women were still in Edwardian corsets, frills and bows, it was Chanel who saw the next new thing - a radical diversion inspired by practical men's clothing.

'That acuity is what Karl feels, too. He moved Chanel on,' she adds, mentioning Lagerfeld's recent turn away from 'girly' in ready-to-wear for outsized volumes, dropped waists and rolled up pants, and low-heeled biker boots.

'He shoots from the hip with an incredible gut instinct and aim. He knows when the next new thing is right - he only has to smell it. It's really thrilling not being afraid of change.'

'Coco is this woman of another time,' says Lagerfeld. 'But the important thing is to make it modern for today - with a relationship to what she was, but completely different. We live in another world.'

This couture collection has a definite futuristic look, recalling early sci-fi films. Harlech's personal favourites from the collection are those that go to the essence of Lagerfeld's design - the simple, timeless pieces that escape trends.

What can we look forward to in future collections from this master of reinvention? 'Without giving it away, Marie Antoinette and tartan,' says Harlech. 'But that's all I can say.'

But don't expect a costumey historical throwback. Lagerfeld wants to maintain the character of Chanel, but he's about creating new ideas rather than looking to the past.

'I hate the idea of vintage,' he says firmly.