Ryouma Echizen, a 12-year-old tennis prodigy, travels to the United States after the National Middle School Tennis Tournament to continue honing his game. Ryouma is pursuing his own path to success in the sport while he looks into a puzzling development: the reasons for his father's withdrawal from the world of professional tennis. Ryouma's father, Nanjiro, is a great tennis player known as "Samurai Nanjiro," whose career ended abruptly after the US Open finals some years before. Even though Ryouma has exhaustively researched the final match, he still has several knowledge gaps that can only be filled by seeing the match live. As fate would have it, the young genius and his unaware classmate Sakuno Ryuzaki are transported back in time by a paranormal event. till that very moment. Even while the circumstances leading up to the game first look regular, the mafia's entry quickly furthers the mystery surrounding the player's retirement. Ryouma must make every effort, despite the slim chances, to figure out the situation and save his father's job.