MADRID, Spain - World No.1 Naomi Osaka probably won't be burning the midnight oil to stay up and follow along with tonight's Met Gala arrivals. She has a second-round match to play against Sara Sorribes Tormo at the Mutua Madrid Open on Tuesday. 

But rumored appearances by Rihanna, Beyonce, Korean pop band BTS, as well as WTA icons Serena Williams and Maria Sharapova, there's no doubt Osaka will be playing catch-up over the next few days.

Oft-described as the most exclusive party in the world, the Met Gala is an annual fundraising gala for the  Metropolitan Museum of Art's Costume Institute in New York City. Chaired by Vogue editor-in-chief and tennis fan Anna Wintour, who Osaka met in January after winning her second major title at the Australian Open, the event has always had strong ties to tennis. 

READ: Serena Williams to co-chair 2019 Met Gala in New York City

Asked whether the Met Gala looks like an event she might enjoy or feel terrified attending, the notoriously shy 21-year-old laughed. 

"A little bit of both," Osaka said after her first-round win in Madrid. "I feel like it would be fun to go to, but then I would have to talk to people and we all know that I don't like doing that. 

"You have to do it once in your life if you have the chance."

"I pay attention to it because I like clothes so seeing like - it's usually Rihanna - she usually does something crazy and she is always really beautiful."

Whether K-Pop megaband BTS will be there is yet to be seen, but asked about her BTS fandom, Osaka laid out her K-pop roots. 

"I got into BIGBANG and 2NE1, especially CL," Osaka said, naming off three big K-pop acts. "I don't know the year, sort of like when 'Crush' and stuff came out.

"And then I just saw BTS doing a lot of related stuff, so I was like who are these kids? Then I slowly started getting into them during the 'I Need U' era." 

World No.1? Check. Two major titles? Check. K-Pop bonafides? Check.