おおきく振りかぶって, 王牌投手-振臂高挥, Ōkiku Furikabutte, 크게 휘두르며, Big Windup!, Grand Swing, Oofuri

The series, set in Saitama, follows the story of Ren Mihashi. Mihashi was the previous ace pitcher in his middle schools baseball team, but it seems that he only got the position because his grandfather was the owner of the school. His teammates (especially the teams catcher, Hatake) hated him, and they always lost their games. Mihashi is thoroughly convinced that he is a lousy baseball pitcher, and feels guilty because he believes that he is responsible for all the losses. Mihashi graduates through middle school with extremely low self-esteem. But in truth Mihashi is really a hardworking and skillful pitcher, and the main reason why his team always lost all the games is because of bad cooperation, because his teammates never talked about the game with him, and they did not try to come up with a plan or strategy to fight against their rivals. Mihashi then transfers to Nishiura High School with plans of quitting baseball because he thinks he is not good enough to succeed at it, though he still loves the game deeply. However, he is dragged into Nishiuras baseball team by their coach, Momoe, while watching the team training outside the field. Assisted by his new teammates (and especially the catcher, Takaya Abe), he grows in stature, confidence and skill, helping his team excel with his own abilities.