Ryouma Echizen is one of 50 nationally ranked middle school tennis players to receive an invitation for the Japan U-17 tennis training camp. Previously open only to high school players, the exclusive regiment trains the best players in the country for the upcoming U-17 World Cup. The high schoolers are not pleased that these middle schoolers are allowed into the camp, but the middle schoolers easily overwhelm them before they are halted by the coaches. The rules of the camp are soon explained: the players are split into one of 16 courts based on skill, with the best players occupying Court 1. Players move up and down courts based on "shuffle matches" that occur before practice begins each day. In anticipation of a game, the middle schoolers are asked to pair up with one another, only to find out that they would not be playing doubles with their partners. Instead, they are pitted against each other in a tiebreaker-style game. The winner of the match would be allowed to stay to further develop their skills whereas the loser would be sent home. For the sake of tennis, friendships and camaraderie are all put on the line. As the fierce competition between the middle and high schoolers persists, the situations they find themselves in goes deeper than just playing to remain in the camp.

After a month abroad, the Foreign Expedition Team has returned to the Japan U-17 training camp. The group consists of 20 players, each with strength and technique that far surpasses those who occupy the camp's top court. In anticipation of the team's arrival, the coaches announce that 20 of the best players would be selected for further training. Tension begins to rise when only high school students are chosen to participate, but the middle school students challenge the players who possess the 11th to 20th positions to steal their places. With the delayed appearance of the "Genius 10," the middle school students begin scheming among themselves to claim those spots as well. Unlikely pairings start to work together, combining their efforts to defeat the top 10 players of the country. It is a battle of wits, deception, and skill—all for the privilege of representing Japan at the U-17 World Cup.

Shouhei Zenya (The Night Before The Invitation) Prior to the U-17 training camp invitations, the middle schoolers spend their last few days of leisure relaxing and goofing off with each other. Kami no Ko vs Koutei (Child of God vs. Emperor) The tiebreaker-style elimination match between Rikkai University-Affiliated Middle School's Seiichi Yukimura and Genichirou Sanada pits two of the "Three Demons'' against each other. As the two fight to stay in the camp, the history between the "Child of God" and the "Emperor'' is revealed. Densetsu wo Tsugusha-tachi (The One That Stands On Top) In the next set of tiebreaker-style elimination matches, Shitenhouji Middle School's Kenya Oshitari and Kuranosuke Shiraishi must face off. As both players have been harboring heavy feelings since the Nationals one year prior, they decide to settle it in this high-stakes match. Shousha no Imi (What it Means to be a Winner) Following the elimination matches, the winners are treated to a luxurious experience after a brutal training session. Some of the middle schoolers contend with each other over the point of the camp now that the losers are gone. They decide to settle their disagreements in the most appropriate way possible: by playing table tennis. Otoko-tachi no Kizuna (Bonds Between Men) After Hyoutei Academy's Choutarou Ootori loses his first court shuffle match, he becomes disheartened and begins to question if he deserves to stay in the camp. Rikkai's Bunta Marui decides to give him some advice to help him overcome his defeat. Tenshi to Seijo (Angel and Bible) The court shuffle matches between Courts 3 and 5 pairs Rikkai's Akaya Kirihara and Shitenhouji's Kuranosuke Shiraishi together. As the game grows progressively more difficult, Kirihara becomes agitated by their opponents. Remembering a promise he made to Kirihara's teammate, Shiraishi must prevent the young boy from losing control of his temper at all costs. Himitsu no Ouji-sama (Prince of Secrets) The middle schoolers become restless and irritated when the camp's food supply begins to run low from a harsh storm. Seishun Academy's Satoshi Horio must deliver a bag to his teammate, Ryouma Echizen, but the angry middle schoolers start to believe that he is hiding food from them. In an attempt to claim the bag's contents, they all begin to fight each other as Horio tries to outsmart and run past them.

The new anime will tell an original story, featuring a match between the Hyoutei Academy Secondary Department led by Keigo Atobe and Rikkai University-Affiliated Middle School led by Seiichi Yukimura. The story was previously not depicted in the manga.