Mari Osaka, the elder sister of four-time grand slam champion Naomi Osaka, said she has retired from playing tennis in her Instagram post on Monday.

"I am retired from playing tennis. It was a journey which I didn't enjoy ultimately but I'm grateful for all the memories and support I've gained and received over the years from the sport," wrote the 24-year-old.

Mari Osaka, the elder sister of Naomi Osaka, speaks at a press conference in September 2018 at Arena Tachikawa Tachihi in suburban Tokyo. (Kyodo)

"I'm moving on now so you can look forward to new fun projects upcoming in the future."

She last played in a women's singles tournament in the United States in January and was ranked 340th in the world as of Monday by the Women's Tennis Association.

The Osaka sisters partnered each other in the doubles during the 2017 Toray Pan Pacific Open in Tokyo.

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