Tuesday's opponent Laura Siegemund was unimpressed by the shiny golden number Osaka donned during their match, insisting, "I come here to play tennis, not to do a fashion show".
After turning heads with a jellyfish-inspired outfit at the Australian Open, Osaka continued her now-famed tradition as she arrived on Court Suzanne Lenglen in a sequined waistcoat blouse and a black mesh floor-length train.
Once the coat came off, she revealed a glittering gold dress with sequins on and she later explained what inspired the kit, saying: "Honestly, it's very couture. Funnily enough, I feel like, you know the Eiffel Tower at night when it's sparkly? I think I look like that a bit."
Osaka appeared to have been inspired by her attire as she was quickly out of the blocks and dominated the first set before Siegemund managed to fight back in the second set, bit the former world No 1 came away with a 6-3 7-6 (7-3) victory.
The unseeded German, though, was not bothered by the four-time Grand Slam winner's "fashion show", but she admits that the time it takes for Osaka to be ready for the match to start is "problematic".
"I couldn't care less," Siegemund told TNT Sports. "I come here to play tennis, not to put on a fashion show. And if others want to put on a fashion show, then they should go ahead and do it. That's totally fine with me.
"I find something else problematic. In our sport, at every tournament, they count every second, right up until you've unpacked your water bottle.
"But she can have a minute and a half to change. I have a problem with that, because these rules simply exist and they are what they are - every second is now being watched so closely for us.
"And I also think that with performances like these, every second should be accounted for. That's the only thing regarding the rules that I don't think is okay and where, once again, bigger names are treated differently."
Osaka gave more background on her attire, which was designed by couturier Kevin Germanier.
"It's just fun to watch designers work, especially when there is an already pre-existing thing that they have to design around, and just to see the ideas," she explained. "We talked back and forth. For me, that's the most interesting part."
Up next at Roland Garros is Donna Vekic in the second round on Thursday and it remains to be seen if she will enter the court with a different dress.