22-year-old tennis star Naomi Osaka made $37 million last year, surpassing Serena Williams as the highest-paid female athlete. Here's how she did it.

Naomi Osaka earned more than $37 million last year.Tim Clayton - Corbis/Getty Images

• Naomi Osaka, at age 22, is the world's highest-paid female athlete with $37.4 million in earnings over the last 12 months.
• On the heels of two back-to-back Grand Slams and on the cusp of playing in the Olympics, Osaka landed several lucrative endorsement deals last year.
• Much of Osaka's career was spent out of the public eye, but her time in the spotlight is only just beginning.

Naomi Osaka is the highest-paid female athlete in the world.

The 22-year-old tennis star raked in $37.4 million in the past year. It's a feat that involves several records broken: Serena Williams was the world's highest-paid female athlete for four years running, and Maria Sharapova previously held the title for the most money earned by a female athlete in a single year.

Osaka has seemingly come out of nowhere. A professional tennis player by the age of 16, she was largely taught how to hit the court by her father and avoided the junior tennis circuit growing up.

Osaka didn't work with her first professional tennis coach until age 18. Within two years, she was finally thrust into the international limelight when she won two Grand Slams back-to-back — which involved a major upset for Osaka's role model, Serena Williams, in the US Open.

Set to compete in the World Olympics for Japan, Osaka now has a string of lucrative endorsement deals under her belt.

A representative for Osaka didn't immediately respond to a request for comment from Business Insider regarding her endorsement deals and their financial details.

Here's how Osaka became the highest-paid female athlete.