(French label Koche made its Japan Fashion Week debut Wednesday, transforming part of Tokyo's famed Harajuku district into a catwalk -- stopping traffic to unveil street cool with a French twist.

Paris-based designer Christelle Kocher brought her two-year old fashion house to the heart of Japanese youth culture, taking over a street lined with boutiques, which until shortly before the show had been bustling with teenage girls dressed in Japan's distinctive school uniforms.

Lanterns lined the open-air runway and a sound system blasted out a techno beat, but otherwise there was no adornment to the display of street wear -- part locker room, part French boudoir.

Kocher cast real people to personify the concept of street fashion, including a Japanese DJ, a photographer and a designer, in a high-energy show presenting more than 40 looks for summer and winter.

Her casting was similar to her 2015 Paris debut, when she turned part of Les Halles into a runway, using models that included what Vogue called a "girl handpicked off the street" and one of her neighbours.

Tokyo on Wednesday saw net leggings, jogging bottoms reimagined as lace flares, patchwork dresses cut on the bias and textured cream silk trousers for men and women, described by Kocher as a unisex look.

There were delicate negligee-style slip dresses and vest tops, paired with denim or sports wear, fabrics with sequins and feathers, and crepe ruffled shirts -- again for both men and women.

"The idea was to bring the energy of Paris together in Tokyo," Kocher explained to reporters backstage after the show.

"We wanted to have this really powerful, symbolic connection between the two countries and show that we can be altogether."

Kocher started the label in 2015 after working for fashion giants Emporio Armani, Chloe, Bottega Veneta and Dries Van Noten.