Mario Tennis (GBC)

Mario Tennis was the story of Alex's rise to become the grand tennis champion of the Royal Tennis Academy.

Royal Tennis Academy
Alex is enrolled as a junior student into the Royal Tennis Academy. Because of his promising skill, he's allowed to enter mid-term, which is pretty rare. He's toured around the Academy by Coach Emily, a member of the Varsity Class. At the end of the tour, Alex is introduced to Harry, who will be his doubles partner and roommate at the academy.

The next day, Alex gets briefed by Harry on how the Academy works: there's no practice schedule; you choose what to practice and how long to practice it. Go to a coach to practice certain techniques such as lobs or volleys.

The Academy's students are split up into several classes, making the match-ups pretty fair; Junior Class, Senior Class, and Varsity Class. Everyone starts in the Junior Class. To move up a rank, you have to become the class champ, which can only be done by matching up against students and moving up the class rankings. Becoming a Varsity member requires being one of the Academy's best players and will also allow you to participate in outside tournaments, but only if you manage to enter the class' traveling team.

Alex then gets to work with moving himself up the ranks. At the Junior Class, he beats Pam, Curt, Beth, and Bob. This qualifies him into the Senior Class, which happened pretty quickly.

At the Senior Class, Alex rises up the ranks by beating Brian, Beth, Allie, and Fay   Alex is granted access to the Varsity Class, which was also done pretty quickly.

After making it to the Varsity Class, Alex is now eligible to reach the traveling team, but only if he manages to beat a traveling team member. Alex manages to beat one in extremely quick succession and is now a representative of the academy.

Island Open
The next day later, everyone in the traveling team is called to the headmaster's office for a meeting, being that they'll be participating in the annual Island Open tournament The next morning, the team departed to the island hosting the Island Open. Alex is bewildered by the sight, while the rest of the team know their way already.

On the Island Open, teams from other schools are present. There's the Academy Team, the Factory Team, the Union Team, and the Empire Team. People have predicted that the Factory Team will win due to the introduction of the Costello twins. Both the Academy and Factory are popular picks for the tournament, likely due to all of the tournament's stars being from Academy.

This bracket tournament had Alex winning all rounds; first, second, and semi-finals. All of Union lost in the first round. Alex' last opponent was against A. Coz, but he managed to come out on top. Alex' victory over the tournament saved Academy's reputation, with a lot of members from other schools being envious in a fairly hostile way. They promise to win against Alex next year, but right now, he won this year's Island Open.

Mario World
Some time later, the headmaster called in Alex to talk about Mario. Alex' fierce style of play made an impression on Mario, and he wanted to invite Alex. Alex accepts and, via plane and entering a portal under a rainbow, arrives at Mario's World.

Alex arrives at Peach's Castle and he is warmly welcomed. Bowser, Wario, & Waluigi assume Alex is here to beat Mario for them in tennis, not to relax. The argument gets out of hand and Princess Peach asks Alex if he wants to play against Mario in an exhibition match. Alex accepts and faces off against Mario. Alex wins the match and is congratulated on stage, receiving a medal with a silhouette of Mario's head on it..

Timeline

 * Bowser, Wario & Waluigi say “We started playing tennis so we could defeat Mario! But we haven’t even come close to beating him…”, implying that this doesn’t happen long after the intro of Mario Tennis (64).
 * Baby Mario is present, placing this game after Mario & Luigi: Partners in Time.