The tennis career of Naomi Osaka, one of the biggest sports celebrities in the world, has taken on certain familiar characteristics during the past 16 months.

Her achievements have been limited on the court because of a series of self-imposed layoffs to manage her struggles with mental health, motivation challenges and the occasional physical ailment, but she has enjoyed wild success off the court, solidifying her status as one of the world’s highest-paid athletes and by far the highest-paid female athlete.

As she sits out the Italian Open to nurse an Achilles’ injury and prepare for the year’s second Grand Slam event, the French Open, set for later this month, Osaka announced that she would be starting a representation agency to take further control of her mounting business portfolio. Osaka and her longtime agent, Stuart Duguid, have left IMG, the sports and entertainment conglomerate, to begin Evolve, which will manage Osaka’s business interests and potentially those of other clients the agency may sign.

News of Osaka’s decision to start Evolve was first reported by Sportico.

A four-time Grand Slam singles champion, Osaka, 24, earned roughly $60 million last year, according to Forbes, with an estimated $55 million coming from more than a dozen corporate sponsors. She was tied for 12th on the Forbes list of top-earning athletes with Tiger Woods. Conor McGregor, the mixed martial artist, held the top spot on the list, earning $180 million.

In an interview Wednesday, Duguid said Osaka’s main priority remained winning tennis matches and tournaments. He said her typical day involves training and treatments with her physiotherapist in the morning followed by lunch, but once that is over, she almost always wants to engage in her cultural or business interests.

“She’s not someone who likes to play video games and binge Netflix all day,” said Duguid, who has worked closely with Osaka since she was a teenager.

Osaka’s ranking has tumbled in the past year and a half, largely because she has played so little. She was ranked second in the world at the beginning of 2021, but dropped to 85th this year. She made the finals of the Miami Open in April, and is up to 38th, and she hopes to climb back into the top 10 by the end of the year.

“I’d be lying if I said I didn’t want to be No. 1 again,” she said at the tournament in Miami.

A spokesman for IMG declined to comment.

Losing a star of Osaka’s magnitude is a significant loss for the company, though it will most likely continue to earn money on existing endorsement deals that it negotiated on her behalf. She is one of a handful of transcendent tennis stars IMG has represented in the past two decades. Roger Federer and Rafael Nadal left the IMG fold in recent years to start businesses with their agents, Tony Godsick and Carlos Costa.

For Osaka, the goal of Evolve is not simply to save money on paying commissions to a third party, but also to grow her business portfolio to $150 million annually in the coming years, from roughly $50 million today, but not by signing deals that put more company logos on her tennis outfits.

Duguid said Osaka might actually pare down her endorsement portfolio. The model for Evolve is similar to businesses set up by several of Osaka’s role models in the sports industry, many of whom have become close friends, including LeBron James and Stephen Curry. Osaka was also close with Kobe Bryant, who died in 2020 in a helicopter crash and who was an early mentor to her.

She has been weighing a venture like Evolve since the Tokyo Olympics, where she lit the Olympic cauldron and was the face of the Games in Japan, her home country. Osaka has wanted more leeway to invest in businesses, have an ownership stake in them and grow her own. She started Kinlò, a skin care products company focused on people with melanated, or darker, skin tones, last year.

That announcement came days after Osaka exited the U.S. Open after being upset by Leylah Fernandez, an unseeded Canadian, in the third round. She announced in a teary news conference after the match that she planned to take an indefinite break from tennis. She had previously taken seven weeks off after she dropped out of the French Open last spring following a conflict with tournament organizers. Osaka had stated that she would not participate in mandatory news conferences after matches. Organizers had threatened to throw her out of the tournament if she did not fulfill her news media obligations, so Osaka withdrew.

Neither the breaks nor her drop in the rankings appears to have affected her ability to grow her business off the court. Now, Duguid said, she will try to retain her leading position off the court as she tries to regain the one she once had on it.

“This is something that scratches an itch on the side for her,” he said.