Little Judo Girl is an action-comedy about a nine-year-old girl named Courtney who has a yellow belt in judo. For the summer, she visits her older cousin Annie. The two hatch a plan to trick boys into play wrestling with Courtney. The kids bet chores on the winner. The local kids have no idea of her judo skills, so she pins and submits many of them including a run-in with the local bully. Then the girls create the "Cabana boy cleaning service" and start renting out the boys to many of the neighborhood girls who kick back a piece of their allowance to Annie and Courtney. The humor is pervasive as some kids go through great lengths to earn their freedom. The story includes coming of age, having respect for others, and some exploring of emotions, but the book is not preachy about these background themes.