If energy creates energy, then Christelle Kocher has certainly tapped a vital source. Along with running Koché, the French fashion brand that will present its spring 2023 collection later this month in Paris, she’s also the creative director of the Chanel-owned Maison Lemarié, one of Paris’s oldest ateliers specializing in handcrafted flower and feather pieces. It’s a job she’s held since 2010, and one that’s thoroughly indoctrinated her into the rarefied world of haute couture.

But there’s more: the 43-year-old designer has also collaborated with brands as varied as Puma, Pucci, and Nike, and with the soccer clubs A.C. Milan and Paris Saint-Germain (separately). Most recently, she designed two collections for the newly revived legendary shoe brand Charles Jourdan. At certain times her work feels omnipresent, even if her name—never mind her likeness—isn’t always visible.

Kocher draws from her athletic background to imbue her line with sporty touches, such as this anorak-style cape.

Having one foot deeply entrenched in the historicism and craftwork of haute couture, and the other in lockstep with the rapidly evolving realm of ready-to-wear, Kocher is ideally suited to be the front-runner in France’s new guard of fashion designers. There are elements of haute couture in Koché, yet the label, which blends streetwear and athleticism with artistic influences, is at its core cool and wearable.

Before turning to fashion in her late teens, Kocher, who grew up in Strasbourg, spent most of her childhood playing sports, specifically handball and soccer. “I came from a working-class background—in the projects, there were basketball courts, or a soccer game in the center,” she says. “Doing sports most of the day was very important.”

Her fixation on athletics persists, both in her designs and her own life, especially from a fitness-and-wellness standpoint. A vegan and avid green-juicer, she regularly practices yoga, kickboxing, Thai boxing, and attends boot-camp classes.

Kocher infuses her collections with a bit of an edge, but she prioritizes wearability, even in her most directional designs.

A graduate of Central Saint Martins, Kocher has a résumé that includes positions at fashion houses such as Emporio Armani, Bottega Veneta, Martine Sitbon, and Dries Van Noten—the latter two of which provided especially formative experiences.

“At Martine, it was such a small team, I had to be able to do everything: the collection, patterns, sketching.... It was the best school ever,” Kocher recalls. “And Dries Van Noten is someone with his own personal point of view, but he’s also an entrepreneur and very business-minded.”

Thanks to her time with Lemarié, Kocher spent almost 10 years working in tandem with Karl Lagerfeld on Chanel’s haute couture collections. If Kocher inherited anything from Lagerfeld, she surmises, it was most visibly his vigor and near-mythical ability to multi-task. “He was always interested in being constantly challenged,” she says. “He was never like, ‘O.K., we did it.’ No, it was always, ‘Now, let’s start again.’”

On the runway at Paris Fashion Week in March.

She launched Koché in 2014, opting to remove the letter r from her own last name to provide a sense of creative distance. The label was never meant to be a solipsistic pursuit, but rather a platform for potential collaborations and expansion into other areas of design. “I could choose to work for one person or do just one thing, but for me that’s not O.K.,” she says.

At her fashion shows, attendees have come to expect an element of surprise, whether it’s in the choice of venue (a casino, New York’s Strand Bookstore, or a passageway tucked off a busy Parisian street, for example) or a humorous wink of some sort. Last season, at her show in Paris, a drone flew out over the runway inside the Westin hotel’s Grand Ballroom, its robotic voice encouraging the audience to “clap your hands, scream, shout and kiss each other.”

“I don’t like to say I’m breaking the system,” Kocher explains with a smile, “but I’m twisting it.”

Laura Neilson is a New York–based writer and a regular contributor to The New York Times and The Wall Street Journal