Pour se rapprocher de celle qu'il aime, Stephen Parker, brillant élève de l'Université californienne de Bramson College se fait passer pour une fille, Stéphanie.
Ryoma Echizen, a tennis prodigy, attends Seishun Academy (also known as Seishun Gakuen or Seigaku, for short), a school famous for its strong tennis club and talented players. Ryoma quickly defeats numerous upperclassmen shortly after entrance to secure himself a spot on the regulars team.
In 1976, Renée Richards is on the tennis court as a professional tennis player. The film flashes back to 1964, when Renée Richards is an eye surgeon named Richard Radley (both roles played by Redgrave). Radley has a successful career and a fiancée, but secretly cross-dresses at night. Unable to speak with his mother Sadie (Louise Fletcher), who is a psychiatrist, Radley consults his own psychiatrist, Dr. Beck (Martin Balsam), who advises him to grow a beard. This strategy works temporarily until Radley is drafted into the Navy, which does not allow beards. Following his discharge and a failed marriage, Radley undergoes gender reassignment surgery and becomes Renée.
Dr. John H. Watson (Robert Duvall) becomes convinced that his friend Sherlock Holmes (Nicol Williamson) is delusional—particularly in his belief that Professor James Moriarty (Laurence Olivier) is a criminal mastermind—as a result of his addiction to cocaine. Indeed, Moriarty visits Watson to complain about being harassed by Holmes. Watson enlists the aid of Sherlock's brother, Mycroft (Charles Gray), to trick Holmes into traveling to Vienna, where he will be treated by Sigmund Freud (Alan Arkin). During the course of his treatment, Holmes investigates a kidnapping case with international implications, and Freud uncovers a dark personal secret suppressed in Holmes's subconscious.
Stevie Castle is a Las Vegas showgirl whose teen daughter K.C. demonstrates a promising aptitude for tennis. But when K.C. enters a local tournament, she encounters hostility and snobbery from the tennis crowd due to her mother's profession.
Jérôme Sauvage aime son travail : la grande distribution, les magasins dans les centres commerciaux, l'adrénaline générée par les responsabilités. Il aime également Laura, sa jolie femme, et leur fils Ugo, 11 ans et graine de champion en tennis. Mais la vie n'est pas simple et son univers professionnel et familial commence à s'assombrir. L'entraîneur d'Ugo lui propose de s'inscrire en section sport-étude où il progresse bien, mais lors d'un tournoi alors qu'il est en difficulté, Ugo va mettre un somnifère dans la bouteille de son adversaire, et son père finit par s'accuser à sa place.
Promising tennis pro Franklin Cane lives in Los Angeles and is mentored by his coach, Jonathan "J.C." Carruthers, who warns him of the perils of success. J.C. advises him to concentrate on his game and not on outside interests, such as a lucrative offer to endorse a hair spray in a TV ad.
The Seishun Academy Middle School tennis regulars are invited on a cruise by Sakurafubuki Hikomaro to play a match with his own tennis team. Aboard the cruise ship, Ryoga Echizen introduces himself to the team as Ryoma's older brother. Ryoma reveals that Ryoga was adopted by Nanjiroh many years ago, when they lived in America, but mysteriously left home prior to Ryoma enrolling in Seigaku. That evening, after a banquet dinner, Takashi Kawamura, being a sushi chef, remarks that the food did not taste as expensive as it looked. In the bathroom, Sadaharu Inui discovers that the marble on the wall is fake when he tears off a piece of wallpaper. It becomes clear that something is not right. The next day, Sakurafubuki reveals to Tezuka and Oishi that they are actually part of an illegal gambling plot. If they purposely lose their matches the next day, Sakurafubuki will rake in a lot of money from people that have betted on Seigaku winning. But, should they choose not listen and win the matches, the team faces the grim possibility of losing their lives.
Venus and Serena takes an unfiltered look into the remarkable lives of the greatest sister-act professional tennis has ever seen. In a sport where they were not welcomed, the indomitable Williams sisters faced the opposition with grace and courage not only breaking new ground for female and African American athletes everywhere, but dominating the women's game for over a decade. The film tells the inspiring story of how these two women, against all odds, but the help of visionary parents, made it to the top.