Harumaki Shunpei is the dedicated leader of the dwindling Karugamo High School Baseball Team. After a demoralizing loss to the Eagles causes multiple players to quit, his team is left with only eight members, one short of being able to field a team. Confronted with this reality, he makes a difficult choice against his own principles and purchases a baseball robot to fill the vacant position. Limited by a tight budget, he acquires an outdated maid robot named Azusa. Though initially ill-suited for the sport, Harumaki and his team soon learn that a secret from Azusa's past could become their key to success.