World No. 2 Naomi Osaka earned her first Olympic berth for Japan on Monday with the release of the international tennis rankings used to determine automatic qualification for this summer's Tokyo Games.

Automatic entry will be awarded to the top 56 men's and women's singles players, with a limit of four per country, and top 10 doubles pairs based on Monday's WTA and ATP rankings.

Naomi Osaka. (Getty/Kyodo)

The singles and doubles draws include slots for the host nation, with Japan possibly receiving additional berths in the case of eligible players withdrawing due to injury or other reasons.

Osaka withdrew from the French Open, which concluded Sunday, after revealing her battle with depression. The 23-year-old pulled out following the first round of the Grand Slam tournament after initially declining to take part in post-match press conferences.

Kei Nishikori dropped from No. 49 to 57 in the ATP rankings, falling out of the top 50 for the first time since September 2011 and relinquishing the position of highest-ranked Japanese men's player for the first time since November 2010.

That honor now belongs to Yoshihito Nishioka, who climbed one spot to No. 56.

Both Nishioka and Nishikori, the 2016 Rio de Janeiro Olympic bronze medalist, are assured entry to the Tokyo Games tournament which will be contested from July 24 to Aug. 1 at Ariake Tennis Park.