SINGAPORE - US Open champion Naomi Osaka admitted Saturday she is still grappling with her newfound stardom but believes the overwhelming attention won't affect her game at the season-ending WTA Finals. The 21-year-old stunned 23-time Grand Slam champion Serena Williams in US Open final. Osaka said her life had changed since the US Open but vowed to remain focused. "With the recognition part, I do feel a bit different," she told reporters in Singapore. "Like before it was only Japan I felt like people knew me. But now like... in the airports and stuff... I just think that's (the attention) kind of funny. For me, I can't change who I am. I haven't really thought about changing my personality. I just focus on my matches, so I just play tennis and I leave the rest up to everyone that I trust."