World number one Naomi Osaka hopes to bounce back from her recent defeats and conquer a new surface as she launches her clay court season in Stuttgart.

The reigning Australian and US Open champion has enjoyed a dazzling rise to the top of women's tennis in the last 12 months, becoming the first Japanese woman to win a Grand Slam and the first Asian player to top the WTA singles rankings.

Having suffered early round defeats in Dubai, Indian Wells and Miami, Osaka is hoping to return to her best form in Stuttgart and chalk up a first major success on clay.

After winning her first professional title at the Indian Wells Open in March 2018, the 21-year-old shot to worldwide fame when she shocked Serena Williams in the final of the US Open last September.

She then held her nerve in a gruelling Australian Open final against Petra Kvitova to win her second major in January.

At just 21, she is already one of the most recognisable names in the women's game. Since signing a sponsorship deal with Nike earlier this month, her face has adorned an enormous billboard overlooking Tokyo's iconic Shibuya crossing.

Osaka, who represents Japan but was raised in the USA by her Japanese mother and Haitian father, has also been heralded as a multicultural star for the global age.

Just last week, she was included in TIME magazine's list of the 100 most influential people of 2019.

"No one represents our more globalized, multicultural future better than (Osaka)," wrote 18-time Grand Slam champion Chris Evert on the TIME list, adding that Osaka would be a "champion for years to come".

- Tough at the top -

Osaka won her second successive Grand Slam title when she beat Petra Kvitova at the Australian Open in January / © AFP

Thus far, Osaka has proven herself a champion on only one surface, with all three of her career titles coming on hard court.

In Stuttgart, she is out to open a new frontier and overcome what she has admitted is a certain trepidation about clay court tennis.

"I have always felt like I could maybe be an all-court player," she told the Guardian in January.

"I think mentally, I don't like clay. I always tell myself I don't like clay, so I never really embrace anything about it and that is something I have to change."

Yet it is not just the perils of a change in surface which Osaka will be battling in Stuttgart.

Since claiming the world number one spot in January, she has also had to adapt to the added pressure of being the woman to beat on the WTA circuit.

She split with her coach Sascha Bajin directly after winning the Australian Open, and has not made the quarter-finals of any competition since.

"I feel like I've dealt with the stress of people asking me if I have pressure because I have the number one next to my name," she said after defeat to Hsieh Su-wei at the Miami Open last month.

"I thought I was doing fine with that, but I guess I'm not."

The star-studded field in Stuttgart means that Osaka could face several players who are currently breathing down her neck in the rankings.

All of the current top five are expected to play in southern Germany next week, and many of them have scores to settle with Osaka.

World number three Kvitova will be out to avenge her Australian Open final defeat, while Osaka also beat Simona Halep and Karolina Pliskova on the way to her Indian Wells triumph last year.