Seigaku travels to England to play a tournament representing Japan but they are attacked by a group of street tennis players who were banned from playing official tournaments because of their rough play.
Twelve year old tennis prodigy, Ryoma Echizen attends the distinguished school of Seishun Academy Middle School with his eyes set on being on the regulars team of the tennis club, which the school is famous for.
The regular players from Seigaku participates in an exhibition game aboard a cruise ship. However, they discover that the event is being run by a corrupt millionaire heavily involved in illegal gambling and betting, who demands that they lose the match on purpose. To add to the confusion, one of the players on the rival team introduces himself as Ryoma's brother.
Hyōtei Gakuen's strange (but impossibly wealthy) captain Atobe Keigo decides to throw a giant party for his friend and teammate Kabaji. He invites both friends and rivals. Together they participate in many different sports and events: dancing, swimming, soccer, a relay race, a haunted house, and more.
Echizen and the Seigaku regulars took a day off of their normal routines and went hiking on a mountain, where a tennis resort awaits their arrival. Expecting to do some special training, the team reaches the destination only to find their precious tennis courts taken over by a group of college tennis players. However, Ryoma is more than happy to teach them a thing or two about how to play “real” tennis.
