县立海空高校棒球部员山下太郎君

Yamashita Tarō, the worst baseball club member in history aiming for the greatest heights. The Kaikō High School baseball club he belongs to is a weak team with no motivation, always suffering first-round mercy-rule losses. During practice one day, they mistakenly believe that the powerhouse school from the same district, Yamanuma High, which happened to stop by on their way back from a practice match, has come to scout them. Furthermore, the Kaikō Nine, taking the Yamanuma players' flattery to heart, embark on intense training. Inspired by Tarō's passion for baseball, they begin to surge forward with unstoppable momentum, winning game after game.