The first time Naomi Osaka skipped over the white Melbourne lettering on the court at the Rod Laver Arena it looked charmingly skittish.

Sometimes a racehorse sees a shadow and jumps, mistaking it for a fence. It appeared a little like that, as if she was suddenly confronted with an obstacle out of the corner of her eye and stepped to avoid it.

Then she did something even stranger as she placed a foot on Melbourne accidentally and immediately regretted it.

She stepped back across it, then returned to her previous place, as if lifting a curse.

For an athlete returning after time out with mental health issues it was not the most reassuring sign, even if Osaka made light of it later.

Obsessive-compulsive behaviour — flicking a switch a certain number of times, avoiding cracks in the pavement — is a condition that affects around 1.2 per cent of people. A tennis player who cannot step on the white lines of a court has a problem and Osaka admitted she does not like doing that either.

In Melbourne, all of the markings are off limits, the lines, the logos. But Osaka has won two of the last three Australian Opens, an incredible achievement given that, as well as focusing on an opponent and marshalling her game, she has to treat the parameters of the playing surface like land mines to be negotiated.

Still, there it is. The mysterious workings of the human mind. Athletes are superstitious sorts. Serena Williams wears the same socks all tournament. Michael Jordan always had on his University of North Carolina shorts under his Chicago Bulls kit. Goran Ivanisevic and Maria Sharapova both had white-line fever when they played tennis.

‘Honestly I’ve always been like that,’ Osaka protested. ‘Every time I’ve come here, I really don’t like stepping on the lines or the Melbourne logo at the back. I’m not really sure why.

‘I would say most athletes have very strong superstitions. It could be one thing or two things. Also I need my water bottles to be completely straight. I’m not sure why.’

This was Osaka’s return to Grand Slam tennis after her second hiatus from the sport following the US Open. Clearly, there are wider issues. Osaka spoke a lot about having fun. She plainly enjoyed a compliment about her outfit, which she described as ‘hot pink’, and dispatched a feisty young opponent in Camila Osorio of Colombia with confidence. Yet sometimes it just seems hard, as if she is searching for the enjoyment in her tennis rather than it occurring naturally.

Even when Andy Murray looks as miserable as sin, appearing to have the weight of several worlds on his shoulders, he absolutely loves playing tennis. Osaka can be decked out in hot pink and skipping around the court like a fawn, but she is actually penned in by chasms of white lines and worrying what people are thinking of her.

‘I would say I feel more comfortable in my skin now, if that makes sense,’ she revealed. ‘There’s always the human nature to feel uneasy, to want to please everyone.

‘There was a time after the French Open where I felt everyone was judging me and I couldn’t go outside without thinking that of everyone. It feels a bit weird when you go into a stadium and you’re concerned what everyone’s gaze means.’

A bit weird? It feels totally traumatising. Even when Osaka missed a forehand smash and laughed rather than castigating herself, it looked a little false as it preceded a small comeback for Osorio, as if she was knocked off kilter more than she would like to admit.

‘I’d say the turning point for me was after the US Open last year,’ the Japanese said. ‘I was just sitting in my house wondering what I wanted to do in the future. I haven’t played Wimbleton in two years. I want to go back and experience that.

‘It’s unfinished business, but also I realised everything can’t be perfect all the time. I now accept the fact that I’ll have dips and I need to figure out a way to overcome that.’

It sounds hard, but shouldn’t be hard. For the girl in the hot pink kit, sadly, it possibly will not ever be any other way.