A baseball team buys a maid robot by accident and has to make it work anyway. Azusa doesn't know the sport, doesn't have an athlete's body, and genuinely doesn't care, she just wants to help her new team win, and that earnestness is the entire joke. The comedy lives in watching a robot with a warm heart and zero baseball sense become the reason nine broken players actually show up to practice.

In 2099, robots are allowed to play baseball, and Karugamo High School's team is on life support. After a humiliating loss to the Eagles, players bail, leaving the roster one short of the nine needed to play. Shunpei, a teenager with a talent for electronics and a love of baseball, goes against his principles and decides to buy a robot to fill the gap. Budget constraints force a compromise, though. Instead of a specialized baseball unit, he ends up with Azusa, a secondhand maid robot. What Azusa lacks in baseball design, she makes up for with a warm heart and strong determination. Still, her rivals are top-of-the-line baseball robots, and she hardly seems to stand a chance. The team's only hope may lie in a secret hidden in Azusa's murky past.