On a day when Naomi Osaka reminded a group of young tennis players from northeastern Japan to remember that tennis is a game and should be fun, she spoke about her experiences as she climbed the rankings this summer.

In her U.S. Open debut earlier this month, Osaka reached the third round, where she blew a 5-1 lead in the third set against world No. 9 Madison Keys of the United States. Afterward, Osaka called her disappointment at Arthur Ashe Stadium, the tournament's center court, "fun."

"Every time I'm learning," she said Sunday at Ariake Tennis Forest Park in Tokyo. "Each occasion is a bit different, but I've kind of adjusted slowly.