After the Nationals, Seishun Academy receives an invitation to compete in a junior tennis championship at Wimbledon. In England, Ryouma Echizen and his teammates are joined by their rivals from Hyoutei Academy, Shitenhouji Middle School, and Rikkai University‑Affiliated Middle School, all of whom have also been invited to this special event. One night before the competition begins, several players are attacked by a gang of thugs, leaving them hospitalized with injuries. The only evidence distinguishing the assailants is a silver ring that each member wears on their hand, and the group"s leader goes by the name Keith.
The middle‑school students convene to discuss their options, but their meeting is interrupted by Ling Xiu—the person who saved Ryouma the night before. Xiu identifies himself as a former member of Clack, a band of tennis players banned from official competition due to their violent playstyles and conduct. He warns the students to stay out of Clack"s affairs, as they cannot hope to win against their style.
Frustrated by the situation, Ryouma sneaks out with Xiu to confront Keith and the other members of Clack, intent on taking them down single‑handedly. Knowing Xiu"s true objective, Ryouma is now more determined than ever to defeat Keith and save him from himself.
