Japan's Ayumi Morita has announced her retirement from professional tennis at the age of 33.

"I, Ayumi Morita, would like to report that I have decided to retire," she wrote on social media. "I will be involved in tennis as a coach in the future, so please continue to support me."

Morita reached her career-high ranking of No.40 in October 2011, one of her five consecutive Top 100 seasons between 2009 and 2013. She did not reach a tour-level final during her career, but she was runner-up at the Nanjing WTA 125 event to Zhang Shuai and made four tour-level semifinals: Strasbourg 2009, Guangzhou 2009, Kuala Lumpur 2010 and Kuala Lumpur 2013.

Morita's best Grand Slam performances came at the Australian Open, where she reached the third round in 2011 and 2013. She notched five wins over Top 20 opponents in her career, defeating Agnes Szavay at Tokyo 2008; Petra Kvitova at Dubai 2011; Ana Ivanovic at Stanford 2011 and Pattaya 2013; and Ekaterina Makarova in Billie Jean King Cup action in 2013.

Known for her two-handed groundstrokes on both wings, Morita was beset by various injuries throughout her career. Having made her WTA main-draw debut at Tokyo 2005 as a 15-year-old wild card (losing 6-4, 6-4 to Maria Kirilenko in the first round), her last appearance at that level came at Kuala Lumpur 2014 (losing 6-4, 6-2 to Lyudmyla Kichenok in the first round).

After a 23-month absence from professional competition in 2020-21, Morita resumed her career on the ITF World Tour in November 2021. She won two titles and reached the Top 600 again, but continued to endure injury issues, retiring in three of her last five tournaments. Morita's final professional match was a 6-1, 7-5 loss to Han Na-Lae in the first round of last November's Tokyo ITF W60 event.

Morita's retirement ceremony will take place on Sep. 9 at this year's Tokyo ITF W100 event at the Ariake Coliseum. She will also host a clinic at the tournament alongside fellow former player Kurumi Nara on Sep. 3.