Gabe Kotter, formerly a Sweathog, returns to James Buchanan High as a teacher and is assigned the remedial class to which he once belonged. Mr. Kotter is an involved and caring teacher, which one would have to be in dealing with a certain four students in his class, who end up in trouble on a regular basis -- lady's man Vinnie Barbarino, the always cool Freddie "Boom-Boom" Washington, the tough Juan (Luis Pedro Phillipo de Huevos) Epstein, and the sheepish Arnold Dingfelder Horshack. Welcome Back, Kotter was based on Gabe Kaplan's own high school experiences with redmedial education and a teacher who cared dearly for her students. Changes on the show. Gabe Kaplan left the series in the third season. He hadn't expected the show to run as long as it had. Kotter was made Vice-Principal, and thus was seen considerably less. John Travolta, of course, found his own place as a celebrity, leaving the show around the same time Gabe Kaplan did (returning every so often as a "spec