Naomi Osaka Arrives to Co-Chair the 2021 Met Gala in Bold Look Co-Designed by Her Sister

Naomi Osaka is serving (pun intended!) high-fashion glamour at the Metropolitan Museum of Art's Costume Institute Gala on Monday.

The tennis champ, 23, arrived at the 2021 Met Gala in a custom Louis Vuitton outfit, featuring a purple and blue swirl-print gown with sweetheart-style neckline and an elaborate black ruffled cape. She amped up the drama by pairing it with black boots and an elaborate hairstyle, accented with red sparkles.

During the Vogue livestream, event co-chair Osaka said her older sister Mari Osaka (who recently retired from tennis) helped design the look along with Louis Vuitton's Nicolas Ghesquière.

RELATED: Everything to Know About the 2021 Met Gala: The Theme, Co-Chairs, Covid Protocols and Beyond

"We both really love fashion and we love designing," Osaka said, adding that they paid homage to the theme of the night (In America) by representing her heritage.

John Shearer/WireImage Naomi Osaka

"For me Americana kinda means a mix of all cultures and this dress and this look kind of represents my two backgrounds, Haitian and Japanese, so I was really glad I was able to incorporate it," she added.

Jeff Kravitz/FilmMagic

The tennis star attended the big night with her boyfriend, rapper Cordae, who was decked out in custom Coach, including a gabardine trench coat with the signature Coach logo on the collar, plus a poplin shirt, gabardine trousers and black lug-sole penny loafers.

ALYSSA GREENBERG

"The look really came together beautifully from the idea we had sent," Cordae tells PEOPLE exclusively. "Coach really brought it to life in a super super dope way. I'm really happy with the final product and more importantly I feel great in the fit."

For more on the 2021 Met Gala and other top stories, listen below to our daily podcast PEOPLE Every Day.

The singer says his partnership with Coach has been a "pretty harmonious."

"It's dope because I've always loved their gear especially as of late," he says. "Plus my mom always had the Coach bags growing up!"

The four-time Grand Slam singles champion isn't just a guest at this year's fête, she's acting as co-chair alongside fellow Gen Z stars Timothée Chalamet, 26, Billie Eilish, 19, and Amanda Gorman, 23, marking the youngest co-chair crew yet (Designer Tom Ford, head of Instagram Adam Mosseri, and Vogue editor-in-chief Anna Wintour serve as honorary chairs).

Be sure to check out all of PEOPLE's Met Gala coverage to get the latest news on fashion's biggest night.

According to Vogue, each co-chair "embodies the defining factor of American style: individualism. They may approach the concept differently, but their shared passion for expressing themselves through clothing connects with the exhibition's theme."

This year's gala kicks off a two-part exhibit, leading with In America: A Lexicon of Fashion, debuting Sept. 18, which will "celebrate The Costume Institute's 75th anniversary and explore a modern vocabulary of American fashion," according to Vogue and exhibit organizers.

For Osaka, she not only developed a signature, colorful style on and off the tennis court, but has become the most in-demand collaborator and designer in the industry.

She has designed collections with Nike, Adeam, and Frankies Bikinis, starred in Louis Vuitton and TAG Heuer ads, and, most recently, designed her own limited-edition four-piece collection with Levi's, which paid special homage to her Japanese heritage.

RELATED: Billie Eilish Will Be the Youngest Met Gala Co-Chair — What Does the Coveted Role Mean?

Osaka previously told PEOPLE she wants to continue down the designer path. "I'd like to start my own brand one day, probably together with my sister," she said of Mari. "But for now I'm loving [collaborating] with some great designers and learning the craft and the business."

Due to the COVID-19 pandemic, this year's Met Gala event organizers have issued a vaccination mandate and mask requirement. All guests are expected to wear a mask indoors except when eating or drinking, a spokesperson for The Met confirmed to PEOPLE.