Naomi Osaka wore a gown that paid tribute to her biracial heritage for her first Met Gala

• Naomi Osaka wore a Louis Vuitton gown with a print of multicolored koi fish to the Met Gala.
• The print was designed by Osaka's sister Mari, who is also a professional tennis player.
• Mari said the design pays tribute to their biracial heritage and "how we all play a role in the American Dream."

The Met Gala is fashion's biggest night, and Naomi Osaka made sure her moment on the red carpet would carry an important message.

The tennis star wore a custom Louis Vuitton gown that paid tribute to both her Haitian and Japanese heritage, according to Vogue.

Osaka - one of the night's co-chairs - helped create the dress with designer Nicolas Ghesquière and her sister Mari for the "In America: A Lexicon of Fashion" theme.

The gown features a multicolored print in bright turquoise and purple that was actually designed by Mari, a fellow professional tennis player.

Mari included koi fish in the design as a symbol of their Japanese heritage.

"The design we ended up creating speaks to our biracial heritage and in that, I believe it really celebrates who we all are and how we all play a role in the American Dream," Mari told Vogue's Liam Hess. "It's a celebration of cultures, like America itself, a melting pot of so many special and unique elements."

Osaka's dress also features a bold red belt and a silk cape with 22 ruffles and 18 meters of leather satin, according to Vogue.

She paired the look with red eye shadow and wore her hair in an updo with braids that sat on top of her head and sparkled with red gems.

"The first time I met Nicolas, we spoke not only about me working with Louis Vuitton as a brand ambassador but also about how we could find ways to work together and even try and co-design," Osaka told the magazine. "So it's a dream come true for me that our first design collaboration is something I will wear on the Met red carpet. The fact that Nicolas, Mari, and I could come together bringing this to life is something I am very honored to be a part of."