The veteran British designer discusses his enduring relationship with the country and its people.

Much has changed in Japan since Sir Paul Smith first visited the country in 1982. “You were a real foreigner back then,” the veteran British designer – who recently launched his new Japanese-inspired capsule collection, available exclusively on MR PORTER – tells me on the phone from his London headquarters. “Very few people spoke English. I remember one day visiting the Imperial Palace in Tokyo – there were about 20 schoolchildren, staring at me like I’d come from the moon. They’d never seen a foreigner before. You can’t imagine that happening now.”

While the country may have changed, the ebullient 72-year-old appears to have stayed much the same. Even over the phone, Sir Paul’s youthful enthusiasm is disarming, and it is easy to imagine the enterprising, fashion-conscious twentysomething who half a century ago opened a tiny shop in Nottingham, selling Kenzo and Margaret Howell, and later his own designs; or to picture the fledgling designer a few years later, in 1976, as he launched his eponymous label in Paris.

Sir Paul has just returned from Chile when we speak, and he tells me enthusiastically how he took some time for a small architectural tour of the country. It neatly demonstrates Sir Paul’s enduring curiosity for the world, as evident today as in that first formative trip to Japan, a trip that established his brand on the international stage and sparked a passion for the country that continues to inspire him to this day.

Drawing from old Japanese textile books, Sir Paul’s exclusive spring collection for MR PORTER centres on a series of printed short-sleeved shirts and shorts emblazoned with flowers and cranes. Set on a colour-fade background in red or blue – a reference to the literal meaning of the Japanese word for “Japan”, Nippon, which translates as “the Land of the Rising Sun” – they are a homage to a country that, until his mid-thirties, he had only dreamt of visiting.

“Like many European and American designers, I had been invited out to Japan to form partnerships with local companies,” says Sir Paul, recalling his inaugural trip to Tokyo. “But I was really more interested in the fact I was going to a country I never thought I’d have the opportunity to visit. I wanted to know more about the culture, the food, the way they made their buildings, their approach to work…”

A wide-eyed appreciation of different cultures has long been key to Sir Paul’s creative process. Although quintessentially a British designer – he trained on Savile Row and is renowned for reinvigorating classic British tailoring – inspiration typically comes from further afield. His famously chaotic office is a haphazard assortment of art, photographs, toys, trinkets, cycling memorabilia and books squashed into shelves or piled up on the desk – all painstakingly acquired from various corners of the globe. “Our design meetings are very much about just leaning back on a chair and pulling out a book,” he tells me. “I work through observation, through travel, through the photographs I take when I’m away, and it all comes together in that crazy office.”

Japan, which Sir Paul estimates he has visited at least a hundred times, has a particular place in his heart. “I’ve got a real affection for the culture, for their way of thinking,” he says warmly when I ask why the place means so much to him. “Even now, I still get excited when I go.” Sir Paul attributes his success in Japan to a genuine passion for the country and its people, citing the fact that many of the designers he was invited out with, all those years ago, didn’t make it in Japan. “I came with a different attitude. I think a lot of the others fell by the wayside because they weren’t curious about the culture here; they didn’t try and immerse themselves in the way of life.”

Today, with more than 200 stores in Japan, Sir Paul has less time to immerse himself in the country than he once did. In those early days – when he would come four times a year, for two weeks at a time – he was able to travel the length of country. He tells me about his love of Kyoto and its history, of the rural north and the mountains, of the bars of Shinjuku in Tokyo, “so tiny and old, so unusual looking.” Now, as an internationally recognised designer and forever in demand, it’s a case of grabbing time when he can. “I sneak off to this little local restaurant, where I just have salmon and miso soup and rice, and the kitchen’s the size of two telephone boxes,” he says, adding, in typically down-to-earth fashion: “I don’t really go to any of the posh, Nobu-type kind of restaurants.”

It’s also in these snatched moments in Tokyo that Sir Paul visits his beloved bookshops: T-Site in Daikanyama, Flying Books in Shibuya – “amazing places that have every book on design, on photography, every magazine”, and which have been a vital source for the patchwork of ephemera that informed Paul Smith’s spring collection. But along with the references to Japanese culture, the collection also draws on Sir Paul’s intimate understanding of the local consumer, using soft, lightweight fabrics that are cool and easy to wear in the often humid Japanese climate.

“And they really are consumers,” Sir Paul says, laughing. “While in the West, we might spend our money on art and furniture, their focus is much more on what they wear, it’s how they express themselves. I think it’s partly why we’ve done so well there.”

In March 2011, Japan was inundated by a devastating tsunami. Tens of thousands died and the country suffered hundreds of billions of pounds worth of damage. Sir Paul was on one of the first flights into the country. “It was around the time that some of my staff and I usually fly out there. Our trip was cancelled, but I still wanted to go by myself,” he says. “The plane was empty – just me and a handful of people going home to their families. I had to go, to be there with my staff, to say ‘I’m with you. I understand.’ It made such a difference to them, and to me.”

Clearly, Japan has proven to be much more to Sir Paul than just an opportunity to licence his brand and expand into new markets. As well as rewarding the designer’s passion and curiosity for the country with commercial success, Japan continues to be a fertile source of inspiration, ensuring that Sir Paul continues to innovate, to be relevant for almost fifty years, win countless awards and a knighthood, after he started selling his own designs in Nottingham. “With Japan,” he tells me, a “it’s more than just a business.”

Shop the Paul Smith collection here