Naomi Osaka and Stefanos Tsitsipas highlighted a parade of WTA and ATP Tour stars on Media Day at the United Cup in Perth Thursday, one day ahead of a likely mixed doubles showdown at the RAC Arena.

In a star-studded Group E, Osaka is spearheading Japan while Tsitsipas, who is playing his first tournament since the US Open, leads Greece alongside Maria Sakkari.

Osaka, who is making her debut at the event, said that she was looking forward to a fun week with her compatriots.

“I’ve always watched United Cup on the TV and I’ve wanted to play for a long time. It’s such a good team atmosphere, which I really enjoy” Osaka said. “It’s nice to have the opportunity to come back to Perth, where I played the Hopman Cup.”

Osaka also opened up about her new perspective on life and her career since the birth of her daughter, Shai, in July 2023.

“My mindset over my career has shifted a lot,” she said. “If you knew me before, you would know that for me, I would take everything so seriously. I would say my losses and my wins defined how I viewed my worth as a person.

“Now I’m just taking it like every day is a new opportunity to do better. But at the same time, I know that my only role, or my biggest role, isn’t a tennis player. It’s to be a mom to my daughter.”

Clocking in from Perth! ⏰#UnitedCup pic.twitter.com/w7WbEobN8v

— United Cup (@UnitedCupTennis) January 1, 2026

Teammate Shintaro Mochizuki said that he was excited to be playing alongside Osaka, who has been a long-time inspiration.

“A couple of days ago was the first time I spoke with her. I was very nervous,” Mochizuki said. “I saw her a couple times at a tournament, but I didn’t get a chance to talk to her… Hopefully I can get closer more and more. If I get to play doubles with her, it would be great. I just want to enjoy the time here in Perth with the whole team.”

Tsitsipas is set to play his first tournament since the US Open after a back injury restricted him to just two Davis Cup matches in the last quarter of the season.

With a broad smile on his face during Greece’s team press conference, Tsitsipas said that he was super keen to kick off the new season with a successful run.

“We’ve had a good team spirit the last couple of years playing the United Cup. It’s been an incredible journey to get started with. Here we are again in Perth. I feel like we can soon be baptised here.

“We’ve played here plenty of times. Perth seems like it’s becoming part of one of the biggest cities of Greece little by little. I’m glad that we’re back.

“I’m really hoping each and every one of our teammates is ready and prepared for war. We are going big. We are fighters. We’re Greek, so we’re going to try to make the most out of it.”

Spain’s Jaume Munar, who is spearheading Spain’s team, is determined to build on his banner season in 2025, when he won 31 matches, more than his combined victories in 2023 and 2024.

“It’s an exciting way to start the season and I’m always happy to be Down Under,” Munar said. “We play individually during the year, so the feeling is great to be playing a team event to kick off the year.

“I always feel honoured representing Spain and the flag and just looking forward for a great week.”

Munar will kick off 2026 play in the United Cup Friday when he plays Sebastian Baez in the first day session match between Spain and Argentina. Tsitsipas and Osaka will be in action for the night session when Greece tackles Japan.

Play in Sydney begins Saturday.

AloJapan.com