"New Prince of Tennis" is a sequel to the original "Prince of Tennis" series, continuing the story of Ryoma Echizen and other talented young tennis players. The narrative picks up after the events of the original series, where Ryoma and his teammates from Seishun Academy (Seigaku) have achieved victory in the National Middle School Tennis Tournament. The sequel shifts focus to a broader stage, introducing the concept of the U-17 Japanese Training Camp, which brings together the best middle and high school tennis players in Japan.

The U-17 Camp is a highly competitive environment designed to identify and train the most promising talents for international competition. Players are divided into two groups: the "First String," consisting of the top-ranked players, and the "Second String," which includes everyone else. The camp employs a ranking system where players can challenge each other to improve their standing. Matches are intense, and the stakes are high, as only the best will be selected to represent Japan in global tournaments.

Ryoma Echizen, the protagonist, initially struggles to adapt to the heightened level of competition at the camp. His journey is marked by personal growth, as he faces off against formidable opponents, including former rivals and new challengers. The series also delves into the development of other characters from the original series, such as Keigo Atobe, Kunimitsu Tezuka, and Shuusuke Fuji, who continue to showcase their skills and evolve as players.

A significant plotline involves the introduction of the "World Cup" arc, where the U-17 team competes against other nations. This arc expands the scope of the series, introducing international players and raising the stakes for the Japanese team. The narrative explores themes of teamwork, perseverance, and the pursuit of excellence, as the characters strive to prove themselves on the global stage.

The series maintains a strong focus on tennis matches, with detailed depictions of techniques, strategies, and the psychological aspects of the sport. Character interactions and rivalries are central to the plot, driving both individual and team dynamics. The blend of intense competition, character development, and the expansion of the tennis world makes "New Prince of Tennis" a compelling continuation of the original series.