In the year 2099, the world of sports has been changed forever due to the addition of athletically inclined robots. For Karu Duck High's baseball club, these expensive opponents on Eagle High's team present a large challenge, especially if they want to win the championship, and their pride! With no money to spend and one player short, the team decides to do the only sensible thing -- purchase a second-hand maid robot to help them win?! As the tournament approaches, this group of students must help a cleaning machine be a baseball star, all without ruining her circuitry!
She cooks, she cleans, and is a lethal fighting machine. Mahoromatic, former Vesper battle android, has chosen to give up her weapons, extending her remaining life from 37 to 398 days. As Misato Suguru's maid, she fights battles of another sort, fending off an amorous teacher on one hand, ecchi magazines on the other. Can Mahoro save Suguru's innocence?