The sitcom revolves around Charlie Goodson (Charlie Sheen), a one-time minor league baseball player who struggled to take the next step due to recurring anger issues. Thanks to a female therapist, Dr. Kate Wales (Selma Blair), Charlie was able to get his issues under control and finally make it to the major leagues. Unfortunately he had a relapse during a big league game, breaking a bat over his knee in anger and causing a career-ending injury. The incident inspired Charlie to return to school and become an anger management therapist. Charlie is divorced from his one-time wife, Jennifer (Shawnee Smith), whom he cheated on multiple times during their marriage.
The two still see a lot of each other, mainly due to having joint custody of their teenage daughter, Sam (Daniela Bobadilla), who has her own issues with OCD. Charlie has a complicated relationship with Kate, who is not only his therapist, but also his best friend and a sex-only love interest. He holds regular group sessions in his home for anger management patients, and also does anger therapy at an area prison.