Last weekend, she was finally freed of the burden after an early exit in the pre-Wimbledon tournament at Birmingham allowed Australian Ash Barty to take over as the WTA's top-ranked player.
Yet on Saturday, all smiles at a pre-event media session at Wimbledon, it appeared that the shy 21-year-old, who has never found the off-court spotlight overly comfortable, seemed far more relaxed about now being the hunter rather than the hunted.
Her spell as the undisputed number one and back-to-back Grand Slam champion saw her skyrocket in global fame and become an iconic figure back in Japan.
"I mean, mentally it was way more stress and pressure than I could have imagined," Osaka explained, reflecting on having to protect the top ranking that she held for 21 weeks after adding the Australian Open title in January to her U.S Open crown.
"I don't think there was anything that could have prepared me for that, especially since I'm kind of an over-thinker.
"So I think it's better for me now to be, like, I was going to say, lower-ranked.
"Isn't that crazy, to be No.2 here, because the only upside is if you win the tournament, you're automatically No.1. That, for sure, is a really big goal of mine. I don't have to think about defending the ranking or anything.
"Also I'm really happy for Ashleigh (Barty). She's super amazing. I think just, like, her whole story of how she quit and came back is super cool."
Osaka believes playing on grass could end up benefiting her power game, though.
"It's been kind of tough (adapting), especially since it's way more unpredictable than clay. But I feel like it should be good for me because it's very heavily reliant on the first serves, (on) being the first person to be aggressive," she said.
"I've been kind of trying to learn every day. I think it's been a very humbling experience."
It could become even more humbling if Osaka's feisty first-round opponent on Monday, Kazakhstan's Yulia Putintseva, repeats her recent victory in Birmingham over the Japanese.
Asked if she was becoming any less of an over-thinker the older she got, Osaka borrowed from the late American rapper The Notorious B.I.G. as she smiled: "You know the song 'Mo Money Mo Problems'? Man, oh, man...
"There might not necessarily be more problems, but I'm definitely over-thinking more."
(Reporting by Ian Chadband; editing by Clare Lovell)
