Ace of the Diamond

Game set. Eijun Sawamura, the pitcher of a novice junior high baseball team, meets with a bitter walk-off loss. For Sawamura, that became his last game in junior high, so he sets a new goal of going to the nationals in high school with his teammates. As he begins his hard quest on studying, a guest arrives unannounced. Her name is Rei Takashima, and she is the assistant director of the prestigious Seidou High School Baseball Team. Takashima invites Sawamura to Seidou after seeing his potential, but Sawamura's reply was far from what she had expected.

Kazuya Miyuki becomes the catcher for Sawamura in a contest against Seido's dangerous clean-up batter, Kiyokuni Azuma. As Eijun tries to pitch down the middle, he finds himself tense and unable to control the ball. Kazuya immediately calls time and comes out to give him some words of encouragement. The words have the desired effect as Eijun finds more control than ever before and unveils a dangerous weapon he didn't know he had. Seeing how people like Kazuya can alter his pitching, Eijun decides to come to Seido as long as he can become the ace of the team.

Eijun is nervous about rooming with older teammates, but they make him feel a too little at home on his first night. Eijun ends up oversleeping and shows up late when it's time to meet Coach Tesshina Katoka, a former Japanese pro pitcher. Miyuki also shows up late, but he uses Sawamura as a decoy to sneak into his line. Katoka shows no mercy and says Eijun can never become a pitcher if he can't show up on time. He also makes Miyuki run laps. Sawamura is determined to prove he can be the ace though, so Coach Katoka gives him a special challenge, saying until he can complete this challenge, he can't play in a baseball game for Seidou.

Seido faces off against Ichidai Third High School, the school that beat them last year. While their top-level offense rakes in runs, the ace Tanba struggles, and the game turns into a batting contest. However Sawamura isn't present. Instead he is training back at school. During his training Furuya, another first-year pitcher, approaches him. Showing sympathy to Sawamura's peculiar training method, Furuya offers to play catch with him. Sawamura is in a cheery mood with Furuya's kindness, but the speed of Furuya's throws far exceeds his expectations.

Coach Katoka, or Shades as Onoda calls him, organizes a game between the first years and the non-starters on the second and third year teams. The goal is to determine who will join the starters for upcoming practice games. When Onoda comes across Katoka in the bath, the coach gives him one final chance to answer his question. After the answer is given, Onoda is allowed into the upcoming game, but when he starts as an outfielder, it could spell doom for any chance he has on the varsity team.

Thanks to the words of fellow first year Haruichi Kominato, Eijun makes it on base. Next Haruichi promises to bring him home and get the first years a run. Haruichi proves to be a brilliant batter, and thanks to his spring Eijun scores. However the first years quickly get three outs, and Coach Katoka says he will call it a game unless all the first years agree to continue. Most want to drop out, but thanks to words of encouragement from Eijun they decide to continue. Eijun is placed on the mound, and Hariuchi is placed at shortstop. The two seem to be wroking effectively together against the older students until Eijun's roommate comes to the plate. Can Eijun find a way to strike out his roommate, who is the #4 hitter for the JV team?