Osaka's time with Mouratologou followed an up-and-down sequence of promising signs and frustrations with either injury or close-run defeats.

Osaka has won only one title while collaborating with Mouratoglou – more precisely the Saint-Malo WTA 125 – really too little for a champion of her caliber, who has made the recent history of women's tennis by becoming a point of reference for all her rivals.

Osaka, a four-time Grand Slam champion, has been in a career rut for years. Mouratoglou joined her staff in September of 2024 and there hasn't been much improvement. Osaka has not made it past the third round of a Grand Slam tournament since 2021 when she won the Australian Open. Now she will look for a new coach to help bring her back to form.