Alex

Alex is a character who debuts in the Game Boy Color version of Mario Tennis. He is the winner of both the singles and doubles championships of the Island Open tournament.

Mario Tennis
In Mario Tennis, Alex was a young boy who received an invitation to join the Royal Tennis Academy as a new student. As he was entering the Academy, the headmaster accidentally ran into him. After properly introducing themselves, they parted ways and Alex ran into Emily, a Varsity Class tennis player and Senior Class coach. She gave Alex a tour of the Academy and introduced him to fellow coaches Kevin and Mark; and to his roommate and doubles partner Harry, whom was also a Senior Class singles player. Alex surprised everyone by easily ranking into the Academy Traveling Team.

Alex entered both the singles and doubles tournament of the Island Open as an unseeded player. Against all odds, he easily defeated the seeded players and made it into the final of both tournaments. In singles, he faced Factory's A. Coz and won easily. In doubles, he and Harry defeated A. Coz and his younger brother B. Coz. News of his accomplishments reached Princess Peach, whom invited Alex and Harry to the Mushroom Kingdom to face Mario, then dubbed "The Greatest Tennis Player of All Time". He defeated Mario in a close match, as well as both Mario and Peach in doubles with Harry.

Alex can be transferred with the Transfer Pak to the Nintendo 64 version of Mario Tennis though not in its Virtual Console ports and Nintendo 64 - Nintendo Switch Online. He retains the same stats from the Game Boy Color version.

Mario Tennis: Power Tour
In Mario Tennis: Power Tour, Alex holds the distinction of being the Academy's best ever player and is still the only one that has challenged Mario before. However, he has retired from competitive tennis and has become the Academy's head coach. Alex develops a training regimen for not just the players, but also for the other coaches, based on the Power Shot that he saw Mario use. At the start of the game, Alex loses the match against Mario, who is wearing a mask to hide his identity. He states that he is surprised that Mario came back for a rematch and wonders when he'll be seeing him again. When Clay or Ace are about to leave to the Mario World after winning the Island Open, Alex tells them a bit about his experience against him and expects the player to beat the plumber. When the player beats the Master level of the Tennis Machine, Alex, along with Nina, come to congratulate the player. Nina proceeds to tease Alex, and reveals that Alex became afraid of the siren that sounds after beating the Tennis Machine.

Trivia

 * In Mario Tennis: Power Tour, it is shown that Alex is canonically the winner of the singles and (along with Harry) the doubles championships of the Island Open.
 * The voice lines for Alex in Mario Tennis (performed by ) are reused assets for Kid from Mario Golf for the Nintendo 64. The lines were later used for Chris in Mario Tennis: Power Tour.