Gabe Kotter wakes up in the morning ready to start his first day as a teacher at James Buchanan high school. When he arrives, Mr. Woodman assigns Kotter to the remedial class, the class he was in years before. Gabe walks into the room and "teaches" class. He's introduced to four main students. Vinnie Barbarino, Juan Epstein, Freddie Washington and Arnold Horshack. The class turns into a disaster and Kotter quits. When Kotter gets home, he and his wife, Julie, get a visit from the Sweathogs. In the end, Kotter returns as teacher.