Naomi Osaka knows baby's gender, but will it be a surprise for beau Cordae?

FLASHBACK: Naomi Osaka honored Serena Williams when the legend announced her retirement last summer.

Boy or girl? Naomi Osaka knows.

The former world No. 1 recently revealed to People magazine that she knows the gender of her unborn child, but that it might be a surprise for her longtime boyfriend, rapper Cordae Amari Dunston, professionally known by the mononym Cordae.

"I've been preparing, but he doesn't know the gender yet, only I know, so it's not like I can build out the room or anything," she said in a February exclusive. "[I'm] just kind of winging it. That's kind of the key motto in my life a little."

Osaka announced in January that she and Cordae, who've been dating since 2019, will welcome their first child later this year. The news came days after she withdrew from the Australian Open, where she is a two-time champion.

Since the news broke, Osaka has nonetheless stayed busy. She unveiled a first-of-its-kind collaboration with clothing company Victoria's Secret, and watched the Kansas City Chiefs beat the Philadelphia Eagles (as well as Rihanna's celebrated halftime show) live from State Farm Stadium in Arizona in Super Bowl LVII.

In her official statement announcing her pregnancy, the four-time Grand Slam champion said she's looking forward to returning to tennis in 2024, saying that her recent sabbatical has given her a new love and appreciation for the sport, and that 2023 will be a "year full of lessons" for her.

She further expanded upon this with People, saying she's looking forward to the "new adventure" that comes with being a first-time parent.

"I think what I'm looking forward to most is the challenges and just learning," Osaka said. "I think there's going to be a lot of things that I don't know, but I have a lot of really amazing people close to me that I can ask questions about. Just a new adventure."