Judo Boy is an adventure story for boys built around the ancient traditions of Judo. Rod Mitchell wants to fight his own battles. After being beaten and humiliated by the school bully and his gang, Rod is determined to fight back. Hearing about Judo from his friend, Mark Takahashi, a Nisei (Japanese-American), Rod joins the Judo school and is soon deep in a strange and fascinating new world.

To his surprise Rod learns that Judo is, first of all, a sport with a strong and inspiring code of sportsmanship. Next he finds that Judo teaches courtesy, respect, and discipline as well as technique. Then, and most difficult of all for the fiery-tempered Rod, he discovers that the best thing a Judoist can do when a fight is starting is to walk away.

Plenty of action, both on and off the Judo mat, keep this story of Rod Mitchell's self-development in Judo exciting. Based on accurate Judo data, it provides an original and valuable view of a new world of sport for boys.