Venus and Serena Williams aren’t the only famous sisters to play tennis on the professional level— just wait until you hear about Naomi Osaka‘s sister, Mari Osaka.

That’s right; the four-time Grand Slam singles champion has a fellow tennis pro in her family. Naomi Osaka‘s older sister, Mari, made her Women’s Tennis Association Tour debut in 2014 and has gone on to compete in four ITF finals since. But how does her tennis career compare to her little sister Naomi’s? After all, the youngest Osaka sister was ranked No. 1 by the WTA in 2021, which certainly makes for some pretty steep competition.

For everything there is to know about Naomi Osaka’s sister—including details about their friendly sibling rivalry and her own tennis career—just keep on reading below!

Naomi Osaka’s sister Mari is retired.

We hate to burst your bubble if you were ever hoping to see Naomi Osaka and her sister face off on the court one day, but for now, it doesn’t seem likely. Naomi’s sister Mari already retired at the age of 25 from the sport. She revealed her decision in March 2021 with a post on Instagram, writing at the time that her career was a “journey which [she] didn’t enjoy,” according to People.

“I am retired from playing tennis. It was a journey which I didn’t enjoy ultimately but I’m grateful for all the memories and support I’ve gained and received over the years from the sport,” Mari wrote in a since-deleted post. “I’m moving on now so you can look forward to new fun projects upcoming in the future.”

Prior to retiring, Mari reached her highest ranking at No. 280 in the spring of 2018, according to Sports Illustrated. And despite being retired, Mari still holds a ranking of No. 335 in the world among women’s tennis players.

Mari always used to beat Naomi at tennis!

Just because Mari retired doesn’t mean that she still can’t give Naomi a run for her money. Back when they were kids, Naomi’s older sister apparently used to beat her all the time in matches. “Up until I was 15 she was 6-0-ing me, ridiculous,” Naomi told The New York Times in a March 2019 interview.

“I don’t know what happened, maybe finally something clicked in my head, but for sure she was beating me,” Naomi said. “In the win-loss record, she’s up by like a million or something.” During a featurette for Naomi’s Netflix documentary in July 2021, Mari also recalled the moment things for her little sister “clicked.” She explained, “the day you caught up to me something clicked… Each win builds a platform that we’ll use to make an impact, finding purpose on and off the court… and cheering each other on.”

Source: Instagram

The featurette, titled “Voices of a Champion,” was first shared via People. During the clip, Mari went on to recount how she and her sister always dreamed big. “We dreamed of being champions. Defying labels, courting excellence, each choosing victory over the other. Our parents organized our dreams and trained us to fulfill them. Their excellence reflecting in our character, in our discipline,” she said. She went on to conclude her sweet ode to Naomi, saying, “Parallel paths. Becoming the champions we need. We dreamed of being champions, Mari and Naomi.”

Naomi and Mari are super close.

According to Naomi, she and Mari practiced tennis together throughout her childhood and formed a tight bond—both on and off the court. During her travels following the 2018 U.S. Open, Naomi recalled how much she missed her older sister: “My sister, I hadn’t seen her in a few months,” she said during “Voices of a Champion.”

Source: Instagram

She added, “I miss her a lot because we grew up together. We would work together every day until we were 17,” noting that, ultimately, she sees herself as “the vessel for whatever [Mari] wants to do.”

Naomi Osaka is available to stream on Netflix.