Every morning Dick Bruna cycles along the canals of the pretty Dutch town of Utrecht to his studio; at exactly eight o'clock he stops for a cup of coffee at the same cafe, where a couple of Japanese girls will be waiting for him. At 78, with a silvery moustache and spectacles, he seems an unlikely target for groupies, many of whom have travelled almost halfway round the world just for his signature and the chance to have their photograph taken with him.
Bruna is the creator of Miffy, or Nijntje (pronounced nein-che, "little rabbit") as she is known in Holland. You may have missed it, but last year Miffy turned 50. For anyone unfamiliar with Miffy, here is a run-down of her globetrotting CV. Since her first appearance in 1955, Miffy has starred in 115 books, which have been translated into 40 languages and sold more than 85m copies worldwide. She has become a cult figure, perhaps more popular among pre-teens than the pre-school market for whom she was originally designed. From the shopping malls of Tokyo to Topshop in Oxford Circus, Miffy merchandising is big business; she is one of Holland's biggest exports, reaching those places that even her main rival, Heineken, cannot reach.
In total, she is worth around $300m (£172m) a year. In Japan, Miffy mania is such that in 1999 giant rabbit-shaped tulip fields were planted in six major cities; and she is so hip that in 2004 she was appointed the official family tourist ambassador to New York City. She might be 50, but this bunny still rocks. As the bestselling writer and British children's laureate Jacqueline Wilson says, "Miffy is an elderly bunny now, but she still looks ultra-chic and stylish." And only the other day, a little girl pulled up alongside Bruna on her bike to tell Bruna, "Miffy is cool!"
This week sees the culmination of her birthday celebrations with the opening a of museum in her honour - the Dick Bruna Huis in Utrecht. As befitting an international style icon of her stature, the museum has been designed by the Amsterdam-based American architect Sherrie Zwail, who recently created the flagship shop for the clothes designers Viktor and Rolf in Milan.
With a permanent collection of his work, Bruna takes his place alongside other Dutch masters, Rembrandt, Mondriaan and Van Gogh; and some of the most prestigious figures in the Netherlands, including members of the Dutch royal family, will be attending the launch.
While Miffy might be an international celebrity and Bruna a millionaire, he is one of the most unassuming men you could ever meet. "I just see it as a very ordinary job. There is nothing else I can do, apart from make little drawings and stories," he says modestly. Entering the studio, where he has worked for more than 30 years, is like walking into a Miffy picture book - everything is white, with splashes of primary colour in the cushions and posters. It is spotlessly clean and tidy, with even the freshly sharpened pencils in neat rows. Among the many drawings from young readers all round the world, there is a cabinet devoted to gifts from Japan, all of them exquisitely handmade: a family of miniature origami Miffys; clay Miffys; Miffy in an embroidered kimono. A few years ago, one Japanese couple even took their honeymoon in Utrecht, turning up on Bruna's doorstep with a Miffy-shaped cake.
All twinkling eyes and gentleness, Bruna is rather like the kindly old puppet-maker Gepetto in Pinocchio; to him, Miffy has become like a little granddaughter. "It seems a little bit silly, but I find it very hard to do even Miffy. I've done so many drawings of her, but every day I try to do it a little bit better than yesterday."
For every Miffy there will have been hundreds of sketches; his wife of more than 50 years, Irene, has the final say on whether Miffy is ready to leave the studio. "I am very nervous. It is like sitting an exam. I can always see on her face if it is a yes or a no. Only if it is yes do I allow the book to be published."
Miffy's eyes and mouth are the hardest. "That's all you have. With two dots and a little cross I have to make her happy, or just a little bit happy, a little bit cross or a little bit sad - and I do it over and over again. There is a moment when I think yes, now she is really sad. I must keep her like that."
Making Miffy sad can take days. Bruna begins with five or six tears and while he is working, he takes a tear away. "At the end I have one big tear, and that is the saddest tear you can have."
What to the untrained eye might look like a bunny with a permanently startled expression is, in fact, a meticulously refined modernist work. Although following a long line of rabbits in children's literature, Bruna's white rabbit is more closely related to the white doves of Matisse and Picasso than Lewis Carroll's white rabbit or Beatrix Potter's Peter Rabbit. Matisse, he says, was his teacher. It was during a trip to Paris to gain experience in publishing, so he could join his father's business, that he first discovered the modernist artists. He was particularly struck by the simplicity of Matisse's collages: "I thought, if I could work like that I would be very, very happy."
Much closer to home, he was also influenced by the developments in Dutch graphic design of the De Stijl Movement, in particular the work of architect Gerrit Rietveld, and his world-famous Schröderhuis, also in Utrecht. And so he embarked on his lifelong quest for ever greater simplicity of form and purpose. And you thought Miffy was just a cartoon bunny.
Miffy began life - like AA Milne's Winnie the Pooh - in stories Bruna made up for his son, Sierk. "It was during the summer of 1955. We had hired a little apartment by the sea, and very often we saw a rabbit running around, so I started to tell him little stories about that rabbit before he went to sleep. Because I was an artist I thought it might be nice to try and draw the rabbit." The result was Miffy at the Seaside. But Miffy was by no means an overnight success. Parents weren't at all impressed: "They said, 'Oh, that's too simple. The colours are too bright and I don't like blue and green together.' But I thought it was nice to make everything as simple as possible to give children lots of room for their own imagination."
In her earliest incarnations, Miffy was simply a nijntje, little rabbit. She was Le Petit Lapin in France and Usako in Japan, where the books were first published in 1964. It was her first English translator, Olive Jones, who christened her Miffy, after deciding that Nijntje was too difficult for non-Dutch readers to pronounce. And it was not until drawing the sixth book, Miffy's Birthday in 1970, when Bruna gave her a dress with flowers on, that he decided "Yes, from now on she's a girl." Over the years she has evolved to become increasingly human: her windsock ears have been tamed, her head is rounder, her features stronger. One thing that hasn't changed, however, is her quizzical gaze. You will never catch Miffy in profile - she is always looking straight out of the page at you.
After noticing that his books were too tall for tiny hands, Bruna simplified even the shape, settling upon the ideal size of 16x16cm. He then found that dividing a sheet from the printers provided him with 12 squares; and he now sees each story as a series of a dozen pictures - any more and it is too long. He still does the black Matisse-inspired outlines with a brush and poster paint, and then transfers them to film. He spent years finding just the one red, blue, green and yellow - now known as the Bruna colours - later expanding his palette for the characters Snuffy Dog, Boris Bear and Poppy Pig, but again agonised over the right shade of grey, brown or pink.
For Dina Rabinovitch, the Guardian children's book critic, "The appeal is in the illustrations rather than the text: stark primary colours on a clean white background - minimalism, loft- living for toddlers - making them immediately identifiable and collectable."
And while it is true that you are unlikely to remember the Miffy books for their stories, which are almost haiku-like in their four-line rhyming scheme, Bruna has tried to keep up with the times in his books, tackling more complicated issues, including race, disability and even death. He is particularly proud of Grandma Bunny, about Miffy coming to terms with the death of poor old Grandma Bun, which won the Silver Slate Award in 1997. "I've never tried to teach children," he insists. "Really, I'm not very good with children, you know. Sometimes I go to schools and I read the story and I'm quite nervous." His favourite title is Miffy at the Gallery, perhaps the most knowing and humorous of all his books, which shows a thoughtful Miffy contemplating works by his heroes Mondriaan, Calder and, of course, Matisse.
It is the graphic austerity of his work that makes Bruna so popular in Japan. An exhibition, Fifty years with Miffy, held at Tokyo's Matsuya department store last year, attracted nearly 200,000 visitors in just two weeks. According to the curator, Daisuke Kusakari, "People of all ages, and even men, buy Miffy products. Japanese people traditionally like simple things, which you can see in old Japanese paintings, architecture and Zen gardens. There are many famous Japanese artists and graphic designers who are influenced by Bruna's creation."
Despite their similarities, Miffy is never to be confused with the Japanese character Hello Kitty, who celebrated her 30th birthday in 2004, and whose popularity rivals even Miffy's. Hello Kitty is bubblegum pink. Miffy wouldn't be seen dead in pink. "It's not a proper colour," decrees Bruna.
Every Miffy product has Bruna's final approval and over the years he has vetoed requests for her to appear on toy guns, racing cars and lingerie. Recently a filmmaker from the Netherlands even proposed an X-rated Porn Miffy: "He was very happy about that, and I was not."
Combined with the books sales, Miffy merchandise has made Bruna extremely rich. "That's what they tell me," he says. But his lifestyle is as simple as his art. He still lives in the same house he bought 40 years ago and he still works seven days a week. Rising at five every morning, he draws a little picture for his wife of something related to her day, a visit to the doctor, a game of bridge; this morning it was a pair of curtains. And every day he cycles back so they can have lunch together. In the evenings he has "a bowl of soup and a nice glass of wine. That's something I like very much".
He owns a small house among vineyards in the south of France, where he goes three times a year and spends the summers with his grandchildren. Are they Miffy fans? Yes, but they read lots of other books too. He doesn't like to push it.
According to the children's author and illustrator Anthony Browne, the picture-book market is in crisis, a result of the trickle-down effect of the Harry Potter phenomenon, with parents expecting ever more sophisticated stories even for very small children. Ironically, as picture books have gone out of fashion, Miffy has become increasingly fashionable; Miffy the icon has almost eclipsed Miffy the character. Emma Arnold, fashion and beauty editor of Girl Talk magazine, aimed at seven to 12-year-olds, often features Miffy items in her fashion shoots. She thinks, "Girls see her as a cute little kitsch symbol. Far from being deemed babyish, she has gained a following of tweens who associate her more with fashion than with pre-school picture books." Sally Johnson, a 12-year-old fan from Wiltshire, says Miffy is both "cool and sweet. I don't think anyone can ever grow out of Miffy. Little children love her because of the books, and I think older people just like her because of the way she looks."
Even Bruna is still perplexed as to why she has been quite such a hit. "When I see children, I think, yes, that is wonderful, but then I just come to the studio and do my work like everybody else. Of course I'm happy that Miffy became quite famous, but if she hadn't I would have carried on just the same. When I am working, I always think I am making a picture book just for myself, for the little boy you have inside yourself."
Naturally, he is thrilled at the opening of the Dick Bruna House: "It's a dream for an artist to have their own museum and for most it happens after they have been dead for a long time. It is very nice to have it during my lifetime. I'm very happy."
So, after more than 50 years, does he think he's finally created the perfect Miffy? "No, I'm going to try and do better today, tomorrow. I just try to make a nice shape, the nicest Miffy I can."
· The Dick Bruna House, Agnientenstraat 2, Utrecht, opens on February 18. See info@dickbrunahuis.nl Happy Birthday Miffy! A celebration of the work of Dick Bruna is at the Ferens Art Gallery, Hull, until April 2 and then tours to galleries in Manchester, London and Edinburgh until June 2007. See www.miffy.com.