A fairy godmother, an overnight transformation, polyester turned into once-in-a-lifetime ball gowns. It may sound cliché, but for Tomo Koizumi, it became reality. For the last seven years, the 31-year-old Japanese designer, who is based in Tokyo, has been quietly making radically vibrant dresses created from acres of organza in topiary-like shapes and colors that run the gamut of the rainbow. Though pop stars including Lady Gaga and the Japanese girl group Perfume have worn his pieces, Koizumi doesn’t sell his clothes in stores and, until recently, he had never presented them during a fashion week. Accordingly, he remained largely unknown outside of Japan.

That was until the stylist Katie Grand introduced herself. Grand, the British consultant to Marc Jacobs and Miuccia Prada who has fostered the careers of designers like Matty Bovan and Giles Deacon, stumbled across Koizumi’s work on Instagram and was so taken aback by his saturated, over-the-top costumes — towering, enveloping pieces made to be worn in the spotlight — that she immediately offered to stage his debut fashion show in New York. Within a few weeks, the actress Gwendoline Christie and the models Bella Hadid and Joan Smalls posed in Koizumi’s dresses, forming a colorful tableau on the staircase of the Marc Jacobs boutique on Madison Avenue. The renowned stylist Guido Palau did the models’ hair; the industry icon Pat McGrath did their makeup; and Koizumi was heralded as the saving grace of an otherwise anodyne New York Fashion Week.

“Everything happened by Instagram,” says Koizumi, still in astonishment. “I already had some samples, but I had to create 14 more to have a full collection — it was just me and my assistant.” Koizumi’s dresses are not exactly everyday garments: Some are made from as much as 650 feet of fabric and are as wide as they are tall. He is uninterested in compromising his vision to create ready-to-wear for retailers (although he likes to point out his dresses are all machine washable — if you have a machine big enough). Instead, Koizumi makes custom dresses for individual clients — usually pop stars or stage performers — in his apartment studio in Tokyo, which he shares with his two pet cats, Khyikhyi and Paan.