At the Mid-County Community Center, a coach quits teaching a ragtag team martial arts. Community Center leader Charlie looks for a new coach but is unsuccessful, until an old friend returns home. Former mixed martial arts champion Jimmy "The Lightning Bolt" Lee arrives. He had been Charlie's protege and father figure for many years. An accident three years ago was supposed to have ended Jimmy's career. When Charlie asks Jimmy to teach the group, he is reluctant at first, but decides to do it while contacting his agent to get him another fight. At first, the kids are reluctant to learn from Lee and each of the kids have issues of their own.