Naomi Osaka became the tennis player to set the Olympic Cauldron ablaze in the opening ceremony. Petra Kvitova, Jelena Ostapenko and Veronica Cepede Royg were flag-bearers for their countries.

The world No. 3 women's tennis star is becoming a Japanese citizen. Tennis phemon Naomi Osaka will give up her U.S. citizenship to compete for Japan at her Olympic debut in Tokyo. Osaka, who was ...