It is an impressive following for a 30-year-old who ran away from home in Tokyo at the age of 14 and who now runs his business from three cramped rooms in All Saints Road, Notting Hill, west London.
Fashion is a fierce business, but some designers stand apart from the fray of competing egos. Tatsuno is one of them - a designer who is demonstrably not in it for money, a member of a fragile elite, working on the perimeters of creativity.
He is a private, retiring individual, blinking uncomfortably in the lights when he emerged at the end of his show to acknowledge the applause. You sensed that he would rather not be there. He is more comfortable in his London studio, where there is barely room to sit; a gap in the hallway is dignified with the name of office.
Tatsuno's experimentation goes on in the back yard. Here he beats, dyes and sculpts. He enjoys creases and frayed edges. He likes to give new life to rough-and-ready materials by mixing them with sumptuous luxury fabrics.
He had no formal training as a designer. 'I like to create in a very spontaneous way,' he says. 'The convention is that you start from a flat fabric cut out on a surface, but that, to me, has nothing to do with the body.'
So he moulds materials on the body to create shapes. He is bored with the smooth fabrics of mainstream fashion. Even the best Italian clothes, he complains, have become predictable.
Tatsuno wants to make fabrics three-dimensional. Sometimes that means working with hi-tech new materials, but more often than not he follows a typically Japanese route: finding the unusual in the ordinary.
In the Nineties, his low-key way of working is likely to be the norm for many young and not-so-young designers. Big business worldwide is cutting back on investment in new names. The international market for high-priced clothes is shrinking.
Tatsuno sees a positive side to all this: a return to a small-is-beautiful philosophy, to the idea of the designer as an artisan, producing one- off pieces for special customers.
The new generation of designers may never make their fortunes, but they may be just as happy working away in their ateliers, making prototype fashion unrestricted by commercial demands. Most of Tatsuno's clothes look like prototypes. Some that he has made with his own hands hang on the walls: a long flowing dress in a double net fabric sandwiching strips of multicoloured beads, others made from pieces of dried seaweed, coils of rope, strips of latex, acid paper, raffia, ribbons.
Tatsuno briefly tried a mainstream route in fashion, linking up with an Italian manufacturer to produce a ready-to-wear collection. He scrapped the deal last year. 'I'm not interested in trying to be another Armani, another Versace. I'm interested in making good clothes for 35 of the best shops in the world. And I am happy with that.'
He came to London at 19, on a buying trip for an antiques dealer, and never went back. One day, he was stopped in the street by a buyer from Browns, the designer fashion store, who asked him about his shirt. Soon, Tatsuno was selling to Browns and designing a label called Culture Shock. He still believes in shock tactics, although there is now a softness about his clothes, in tune with the gentler mood filtering through fashion in the mid-Nineties.
Why does he stay in London? 'I would do better in Paris, perhaps, but this is where all the creativity is. This country still has all the talent.'
Koji Tatsuno is available from Browns, 23-27 South Molton Street, W1; Joseph, 77 Fulham Road, SW3; Liberty, Regent Street, W1; Whistles, 12-14 St Christopher's Place, W1; Koji Tatsuno/Geannette, 2 bis Rue Gribeauval, 75001, Paris; inquiries 071-221 7481.