Louis-Gabriel Nouchi, of the Paris-based fashion brand LGN, was thrilled when he got the phone call asking him to design the costumes for the Paralympics’ opening ceremony, which was held on Wednesday in Paris, with a procession down the Champs-Élysées that ended at the Place de la Concorde.

“I wanted to put all my heart into this project,” said Mr. Nouchi, 36, “because it was the Paralympics, you know, and it was really close to me personally, because I’m working a lot on inclusivity at LGN in terms of plus size, age and diversity of bodies on the runway during fashion week.” Mr. Nouchi, who is known for manufacturing elegantly simple men’s wear with a punchy contemporary twist, grinned through a video call in which he was sporting a thick mustache and a simple black T-shirt and smoking a cigarette throughout the interview.

The Paralympics assignment did not immediately elicit in him a sense of patriotism. Though Mr. Nouchi grew up in Paris, he was trained in Belgium and worked in Italy during his early career, and he said that his time outside France had been a major influence on his identity as a designer. But the process of designing hundreds of garments for performers with disabilities brought forth his latent pride in his country.

“I was becoming more and more patriotic as I was working on this project,” Mr. Nouchi said. “The more I was doing rehearsals and fittings, the more proud I was. And you know, it’s difficult for French to be proud of being French.”

The brief was straightforward, but it was also an enormous undertaking: create approximately 700 items of clothing for performers with disabilities to wear during the festivities. Mr. Nouchi said he knew from the outset that he didn’t want to create costumes. Rather, he wanted his clothing to play a supporting role in the show. The clothing should have an urban, Parisian sensibility and, crucially, be comfortable. He didn’t want his garments to overshadow the performers or the event itself.