Synopsis
During middle school, Hiro Kunimi (pitcher), Hideo Tachibana (third baseman and 4th batter), and Atsushi Noda (catcher) were friends and teammates on the same baseball team. Thanks to their skills, their school achieved an unbeaten record on their way to consecutive national championships.
In the seventh grade Hiro also played matchmaker to Hideo and Hikari Amamiya, a neighborhood childhood friend who grew up with him as close as a sibling. At this time Hiro, victim of a delayed growth spurt, was a very short, comparatively immature boy, uninterested in girls, and initially happy that he could get the two of them together. Eventually Hiro realized that he too had feelings for Hikari and, once he grew up, Hikari also realized that her affection for Hiro might be something more than sisterly.
As the manga begins Hiro is dealing with a doctor's diagnosis that tells him that, if he continues pitching, his elbow would shatter within three months. Likewise, Noda is diagnosed with a severe back injury by the same doctor, seemingly ending their dreams of Kōshien. Because of this, Hiro and Noda choose to go to Senkawa High School, which lacks a baseball team; Hiro instead joins the soccer team and Noda, the swim team. Their friends, Hikari and Hideo, attend Meiwa Daiichi High School, which boasts one of the top-ranked high school baseball teams in the country.
While Senkawa does not have an official baseball team they do have a baseball "fan club," voluntarily managed by the cute but klutzy Haruka Koga, a girl Hiro keeps running into- literally. While a member of the soccer team, Hiro is drawn into a practice baseball game between the soccer team and Haruka's fan club. Disgusted by the demeaning behavior of his team captain and the pompous 1st year star player, Ryūtaro Kine, (once an accomplished Little League pitcher), Hiro decides to switch sides and pitch "one last game" for the fan club. Joined by Noda, they very nearly come from behind and overcome the soccer team's large advantage in just a couple innings, but do succeed in rallying the demoralized fan club and embarrassing the soccer team.
Soon after it is revealed that the doctor who diagnosed Hiro and Noda was actually a quack and they have no lasting injuries, meaning they can return to playing baseball. Instead of transferring to Meiwa Daiichi or another school with a baseball team they decide to accept their fate and, with the help of the fan club and Haruka, persuade their "baseball-hating" headmaster to establish a proper baseball team. They succeed in this by playing Meiwa Daiichi in a practice game they were not expected to do well in. Although Senkawa ultimately loses the game by a single run (because a Meiwa Daiichi umpire lies about a call to give them the win), the game rekindles the headmaster's former love of baseball and he allows the club to be formed.
Led by novice coach Fujio Koga, Haruka's brother, the team plays their first game as an official team against the Northern Tokyo Division's leading team, Eikyo High School, in what is supposed to be a friendly practice match. Although Eikyo easily wins, the game and stories about the team reveal that the veteran coach and the famed first-year pitcher Hirota share a ruthless "win-by-any-means" game philosophy that includes purposefully injuring rival players and shunning players that do not obey them, no matter how skilled they are.
In their second year, the new baseball club gains three notable members: Sagawa, Shima, and Ohtake. Sagawa is an old friend of Hideo's who also has a reputation as a one-time delinquent, and the latter two are relatives of Hirota, planted by him to destroy Senkawa from within at his command. All eventually grow used to the friendly atmosphere of the Senkawa team and prove to be extremely valuable team members. In the final game of the divisional tournament Senkawa defeats Eikyo, advancing to the National Koshien Tournament, vindicating their style of play and specifically Coach Koga and Sagawa, who were separately both previous victims of the Eikyo coach and Hirota.
Senkawa were set to meet up with Meiwa Daiichi after two opponents in the Koshien tournament, a duel between the friends and rivals: Hiro and Hideo. This is foiled when Senkawa loses in the ninth inning of the second round when Hiro sprains his foot while dodging the opposing pitcher's hand, which was tagging first base directly under his spiked cleats. Meiwa Daiichi went on to win this Summer Tournament.
Around this time Hiro admits to Hikari that he fell in love with her in the eighth grade and still feels strongly for her. Yet at the same time he is also struggling with his feeling for Haruka and does tell her "I love you" after a situation in which he defends her from a fellow student who tried to force himself on her. Although they are much closer after this it is not certain they are officially dating.
Meiwa Daiichi fail to win their division in the Fall tournament, after the departure of their third year players, and are not invited to the Spring invitational Koshien. This leads to Hiro and Senkawa winning the national Spring tournament without facing them.
Between the Spring and Summer tournaments a passing Hikari luckily saves the life of Hiro's mother, whom she found on the floor suffering from an acute appendicitis, but soon after loses her own mother to a sudden and unexplained illness. This devastates both Hikari and Hiro, who loved her as a second mother. Hikari is greatly comforted by a very attentive Hideo but only cries with Hiro.
Right before their last summer tournament starts Hideo tells Hikari that she must choose between him and Hiro once they face each other in what he believes is their fated showdown at Koshien. Sure enough, Senkawa and Meiwa Daiichi both advance to meet in the semi-final match. Hiro only learns that Hideo made this ultimatum to her the night before the game. Hiro keeps Hideo hitless through three at bats and protects a Senkawa 2-0 lead as he faces Hideo for a final showdown with two outs in the bottom of the ninth inning. Hideo very nearly hits a home run but it goes barely foul due to a brief gust of wind in the stadium. On the final pitch, Hideo momentarily second-guesses which pitch Hiro is throwing and strikes out, ending the game. As Senkawa celebrates their victory, tears fall from Hiro's eyes, but also from Hikari's eyes as she watches from the stands.
That night, Hideo talks with Hikari and admits his defeat to Hiro but she tells him that she never had the right to choose between them. Hideo then tells her that the loss made him realize that he needs Hikari more than anyone else. They embrace. The next morning, Hiro implies to Haruka that he intends to play baseball as a professional by tossing a paper airplane that he says is "traveling to the major leagues" and Haruka declares her decision to accompany him by saying "then I will be the stewardess," referencing an earlier conversation where she said she wanted to become a stewardess, which she sees as a fitting job for the wife of a baseball player.
Having resolved the real conflicts of the story, the manga ends with Senkawa traveling in their bus to play the final game of the Koshien, never revealing if they win or not.
