Mr. Woodman takes over Mr. Kotter's social studies class for a week to teach the Sweathogs about American history, and to prove that he still has what it takes to be a good teacher.
When a new girl, Sunny, comes to the Sweathogs classroom, all the boys try to impress her to become her boyfriend. But when she makes a pass at Gabe, he reaches out to find her true story.
Arnold has been promoted to a regular classroom against his wishes to remain a Sweathog. When Mr. Kotter teaches the guys to let him move on so that he can be the best Arnold possible, his plan backfires when Arnold feels no one likes him anymore.