Casey is attacked at random on the street and enlists in a local dojo led by a charismatic and mysterious Sensei in an effort to learn how to defend himself. What he uncovers is a sinister world of fraternity, violence and hypermasculinity and a woman fighting for her place in it.

Goofy takes a lighthearted look at self defense through the ages: cavemen, knights, the age of chivalry, and finally boxing.