Three high school girls serve as managers for their school’s baseball club, though each has a very different reason for taking on the role. Akane Nagisa knows almost nothing about the sport and joined solely because she thought it would make her popular. Karina Ichinose, a fashionable gyaru, became a manager out of a genuine love for baseball, a fact that surprises the others given her appearance. Yuki Himemiya originally joined because her boyfriend at the time was a member of the team, and she continues in the role even after their breakup.

The story is set within the baseball club of a typical Japanese high school. Rather than focusing on the games or the players' athletic journeys, the series follows the daily lives and playful hijinks of these three managers as they handle their duties. Their tasks include preparing rice balls for the team, cleaning the equipment room where they occasionally discover adult magazines, and offering various types of support to the players. Their different personalities drive the comedy. Nagisa is relentlessly cheerful but often clueless, Karina acts as the grounded straight woman who comments on the absurdity around her, and Yuki appears sweet on the surface but frequently reveals a mischievous, sometimes unexpectedly lewd, side.

Key character dynamics add further layers to the narrative. Nagisa is childhood friends with Karasuma, a skilled player who is quietly developing romantic feelings for her, though Nagisa remains completely oblivious to his attention. Yuki is currently dating another club member, Shimohara, and her relationship often becomes a source of speculation for her friends due to her suggestive comments. Recurring gags include the three managers accidentally creating misunderstandings with their actions or conversations, which are frequently overheard by a background player named Hayashi, who misinterprets their innocent activities as something far more scandalous. The story weaves these character-driven moments into a lighthearted slice of life, where the managers grow closer as friends while navigating their youth on the sidelines of the baseball field.