US Open champ Naomi Osaka earned $3.8 million—here's what she plans to do with her prize money

Naomi Osaka of Japan celebrates her semi-final win over Madison Keys at the 2018 US Open 
Matthew Stockman | Getty Images Sport | Getty Images

In Saturday's controversial US Open final, Naomi Osaka of Japan came out on top, defeating her childhood hero Serena Williams, 6-2, 6-4.

The 20-year-old became the first Japanese-born tennis player to capture a Grand Slam title. Besides making history, she walked away with a cool $3.8 million paycheck.

When asked if she was going to treat herself to anything after the win, nothing materialistic came to mind. "I'm not really the type that spends money on myself," she told reporters in the post-match press conference. "For me, as long as my family's happy, I'm happy. So when I see my sister … for me, that's the biggest gift."

Venus and Serena Williams fought for equal pay at Wimbledon — here's their next big challenge

It's similar to what Williams did after earning her first million: Rather than splurging on anything, she deposited it directly into the bank and walked away, she told Maverick Carter on an episode of "Kneading Dough."

Tennis has never been about getting paid, added Williams. In fact, she used to forget to collect her paychecks altogether: "When I first turned pro, you had to go pick up your check. I never, never picked it up, so at the end of the year, the tournament directors would literally hand me the check because I would never go get it."

The saving mentality runs in the family: When her sister Venus earned her first big paycheck, she also sent it straight to the bank.

"I really didn't spend any of it," the tennis star tells CNBC Make It. "I just didn't want to become a statistic, or one of those athletes that had it all and then in the end had nothing. That was always in the back of my mind, so it made me want to be more realistic with how I spent money."

Don't miss: Here's what Venus Williams did with her first big paycheck—and it's not what you might expect

Like this story? Subscribe to CNBC Make It on YouTube!

Venus Williams saves most of her prize money—but she has one guilty pleasure