Haru Shirokane and Taiga are saved from a group of delinquents by the strongest XB player and leader of the Minato Tribe, Shun Kamiya. Despite calling him boring, Kamiya invites Haru to his Extreme Baseball team with Taiga joining too. In the match against a rival team. In the aftermath, Haru overcomes his weakness and decides to stay with Shun in the team.

Hull and Taiga are fascinated by XB and decide to join Minato Tribe. The two learn the rules of XB from the deputy leader Saori Arisugawa, but Taiga, who is not good at studying, is not good at it. Kamiya, who was watching the situation, proposes a practice game, saying, “It is faster to actually play.”Meanwhile, at that time, King Neo Tokyo’s Ho-Oh Tenshin had given a certain order to Chiyoda Tribe, led by his successor, Ho-Oh Jiro.

A member of Minato who is defeated by Ojiro and despairs. The life of the tribe was disbanded, and my body and soul were about to fall apart. At that point, an incident occurred in which Arisugawa was kidnapped by Hyakutaro Senju of Adachi Tribe. The remaining Minato members are confused, but head to Adachi City to help Arisugawa.

Minato started XB with Adachi to help Arisugawa, but he was at the mercy of how to fight by taking advantage of Adachi’s land. Kazuki Aoyama, a mysterious man who suddenly approaches “Let’s help” in front of such Minato members. Due to his strategy, Minato quickly regains his position and begins to catch up with Adachi. Haru and Taiga were antipathy to Kazuki’s mocking attitude and way of doing things.

After the battle with Minato, Senju had another unpleasant existence. He is Chiyoda’s King Jiro, who is crushing the tribes in Neo Tokyo. Senju decides to hit Chiyoda. Haru and his friends, who once lost the battle with Chiyoda and know their abilities, try to stop the battle because they are worried about Senju.

Kazuki urges Taiga to practice away from Minato. Hull, who witnessed the appearance, deepens his distrust of Kazuki. At that time, an incident occurred in which a thief entered the hideout in an attempt to steal Hull’s beam bat. Maybe that thief is …

Chiyoda’s Yui Kamiki visited Otatribe to request the killing of Kazuki Aoyama. Until then, Otatribe was dressed in poor clothes and pretended to be a beggar … Its true identity is a brutal bandit led by Sonoda, a leader who loves chaos. At the request of Shinboku, Sonoda and his colleagues start attacking Minato Tribe without regard to the XB method.

In the midst of the battle with the confused Ota, Sonoda’s mouth tells Kazuki’s true purpose. It was “to use Minato Tribe to take revenge on Ojiro who broke his left arm.” Hull and others who knew it could not find the meaning of continuing the battle and tried to abandon the game. However, only Taiga, who returned from training, did not lose his will to fight …!

After overtaking the throne, Ojiro enacts brutal XB laws and issues a challenge to Minato Tribe. The crew questions whether to take him on when the game has become a bloodbath.

Before the game gets started, Haru has something important to say. But just when the crew thinks they have a fighting chance, Chiyoda Tribe gets serious.

Ojiro himself has taken the field and is determined to crush all opposition. Kazuki struggles to win back his old friend as Haru fights to protect all he holds dear.