Serena Williams and Naomi Osaka will take part in a livestreamed 'Mario Tennis' tournament with a $1 million charity prize

· Tennis players including Serena Williams and Naomi Osaka will take part in a charity doubles tournament on "Mario Tennis Aces" on May 3.
· Tennis players will be paired with celebrities including Seal and Gigi Hadid.
· Each participant will receive $25,000 to donate to the charity of their choice, and the winners will get...